diff --git a/docs/custom-domain-validation.md b/docs/custom-domain-validation.md
new file mode 100644
index 000000000..a70388e4d
--- /dev/null
+++ b/docs/custom-domain-validation.md
@@ -0,0 +1,28 @@
+A new custom domain name is converted to lowercase ASCII (punycode), with a
+trailing dot removed, before availability and DNS validation checks. Invalid
+names and wildcard registrations are rejected before storage.
+
+A custom domain registration must complete validation within 48 hours of
+creation. Retrying validation does not extend this window. Once validation
+succeeds, the registration is exempt from this expiration policy.
+
+Management removes expired, unvalidated registrations at startup and every
+60 minutes. While management is running, removal normally occurs between
+48 and 49 hours after registration. Validation is refused after the 48-hour
+deadline even if cleanup has not yet removed the registration.
+
+Removal releases the name for a new registration. The new registration must
+complete its own validation. Its account does not inherit validation or
+services from the expired registration.
+
+The original account receives a system activity event named
+`CustomDomainValidationExpired`, displayed as "Unvalidated domain registration
+expired". The event includes the domain name, original registration ID, and
+validation deadline.
+
+On upgrade, existing unvalidated registrations receive a 48-hour validation
+window. Restarting management does not extend a previously assigned deadline.
+
+Registrations with existing services, including services using subdomains, are
+retained for operator review. Management logs their account and domain IDs so
+an operator can identify and resolve those dependencies before cleanup.
diff --git a/management/internals/modules/reverseproxy/domain/domain.go b/management/internals/modules/reverseproxy/domain/domain.go
index 08d7ad19b..74583c55f 100644
--- a/management/internals/modules/reverseproxy/domain/domain.go
+++ b/management/internals/modules/reverseproxy/domain/domain.go
@@ -1,5 +1,13 @@
 package domain
 
+import "time"
+
+// ValidationTTL is the time available to validate a custom domain registration.
+const ValidationTTL = 48 * time.Hour
+
+// ID identifies a custom domain registration.
+type ID string
+
 type Type string
 
 const (
@@ -8,12 +16,13 @@ const (
 )
 
 type Domain struct {
-	ID            string `gorm:"unique;primaryKey;autoIncrement"`
-	Domain        string `gorm:"unique"` // Domain records must be unique, this avoids domain reuse across accounts.
-	AccountID     string `gorm:"index"`
-	TargetCluster string // The proxy cluster this domain should be validated against
-	Type          Type   `gorm:"-"`
-	Validated     bool
+	ID                  string `gorm:"unique;primaryKey;autoIncrement"`
+	Domain              string `gorm:"unique"` // Domain records must be unique, this avoids domain reuse across accounts.
+	AccountID           string `gorm:"index"`
+	TargetCluster       string // The proxy cluster this domain should be validated against
+	Type                Type   `gorm:"-"`
+	Validated           bool
+	ValidationExpiresAt *time.Time `gorm:"index"`
 	// SupportsCustomPorts is populated at query time for free domains from the
 	// proxy cluster capabilities. Not persisted.
 	SupportsCustomPorts *bool `gorm:"-"`
@@ -36,7 +45,12 @@ func (d *Domain) EventMeta() map[string]any {
 	}
 }
 
+// Copy returns a copy with an independent validation deadline.
 func (d *Domain) Copy() *Domain {
 	dCopy := *d
+	if d.ValidationExpiresAt != nil {
+		expiresAt := *d.ValidationExpiresAt
+		dCopy.ValidationExpiresAt = &expiresAt
+	}
 	return &dCopy
 }
diff --git a/management/internals/modules/reverseproxy/domain/manager/expiration.go b/management/internals/modules/reverseproxy/domain/manager/expiration.go
new file mode 100644
index 000000000..381e3ca51
--- /dev/null
+++ b/management/internals/modules/reverseproxy/domain/manager/expiration.go
@@ -0,0 +1,73 @@
+package manager
+
+import (
+	"context"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/management/internals/modules/reverseproxy/domain"
+	"github.com/netbirdio/netbird/management/server/activity"
+)
+
+const (
+	validationCleanupInterval = 60 * time.Minute
+	validationCleanupBatch    = 100
+)
+
+// RunValidationCleanup removes expired registrations on startup and hourly until cancellation.
+func (m Manager) RunValidationCleanup(ctx context.Context) {
+	ticker := time.NewTicker(validationCleanupInterval)
+	defer ticker.Stop()
+	for {
+		m.cleanupExpiredDomains(ctx, time.Now().UTC())
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+		}
+	}
+}
+
+func (m Manager) cleanupExpiredDomains(ctx context.Context, now time.Time) {
+	var afterID domain.ID
+	for ctx.Err() == nil {
+		domains, err := m.store.GetExpiredCustomDomains(ctx, now, afterID, validationCleanupBatch)
+		if err != nil {
+			if ctx.Err() == nil {
+				log.WithContext(ctx).WithError(err).Error("list expired custom domain registrations")
+			}
+			return
+		}
+		for _, d := range domains {
+			if ctx.Err() != nil {
+				return
+			}
+			m.deleteExpiredDomain(ctx, d, now)
+			afterID = domain.ID(d.ID)
+		}
+		if len(domains) < validationCleanupBatch {
+			return
+		}
+	}
+}
+
+func (m Manager) deleteExpiredDomain(ctx context.Context, d *domain.Domain, now time.Time) {
+	deleted, err := m.store.DeleteExpiredCustomDomain(ctx, d, now)
+	if err != nil {
+		if ctx.Err() == nil {
+			log.WithContext(ctx).WithFields(log.Fields{"accountID": d.AccountID, "domainID": d.ID}).
+				WithError(err).Warn("could not expire custom domain registration")
+		}
+		return
+	}
+	if !deleted {
+		return
+	}
+	meta := d.EventMeta()
+	if d.ValidationExpiresAt != nil {
+		meta["validation_expires_at"] = d.ValidationExpiresAt.UTC().Format(time.RFC3339)
+	}
+	m.accountManager.StoreEvent(ctx, activity.SystemInitiator, d.ID, d.AccountID,
+		activity.CustomDomainValidationExpired, meta)
+}
diff --git a/management/internals/modules/reverseproxy/domain/manager/expiration_test.go b/management/internals/modules/reverseproxy/domain/manager/expiration_test.go
new file mode 100644
index 000000000..e3b05efbb
--- /dev/null
+++ b/management/internals/modules/reverseproxy/domain/manager/expiration_test.go
@@ -0,0 +1,274 @@
+package manager
+
+import (
+	"context"
+	"fmt"
+	"sync"
+	"testing"
+	"testing/synctest"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/management/internals/modules/reverseproxy/domain"
+	rpservice "github.com/netbirdio/netbird/management/internals/modules/reverseproxy/service"
+	"github.com/netbirdio/netbird/management/server/activity"
+	"github.com/netbirdio/netbird/management/server/mock_server"
+	nbstore "github.com/netbirdio/netbird/management/server/store"
+)
+
+func TestValidateDomain_ExpiredRegistration(t *testing.T) {
+	env := setupDomainTest(t)
+	ctx := context.Background()
+	d, err := env.manager.CreateDomain(ctx, accountA, accountAUser, "expired.example.com", testCluster)
+	require.NoError(t, err)
+	expiresAt := time.Now().Add(-time.Second)
+	db := env.store.(*nbstore.SqlStore).GetDB()
+	require.NoError(t, db.Model(&domain.Domain{}).Where("id = ?", d.ID).
+		Update("validation_expires_at", expiresAt).Error)
+	env.resolver.set("validation.expired.example.com", testCluster)
+
+	env.manager.ValidateDomain(ctx, accountA, accountAUser, d.ID)
+
+	stored := storedDomain(t, env.store, accountA, d.Domain)
+	require.NotNil(t, stored)
+	assert.False(t, stored.Validated, "an expired registration must not become usable before cleanup runs")
+}
+
+func TestCreateDomain_ValidationDeadline(t *testing.T) {
+	env := setupClockDomainTest(t)
+	synctest.Test(t, func(t *testing.T) {
+		ctx := context.Background()
+		createdAt := time.Now().UTC()
+		d, err := env.manager.CreateDomain(ctx, accountA, accountAUser, "pending.example.com", testCluster)
+		require.NoError(t, err)
+		require.NotNil(t, d.ValidationExpiresAt)
+		assert.Equal(t, createdAt.Add(48*time.Hour), *d.ValidationExpiresAt, "new registrations get 48 hours")
+
+		time.Sleep(time.Hour)
+		env.manager.ValidateDomain(ctx, accountA, accountAUser, d.ID)
+		stored := storedDomain(t, env.store, accountA, d.Domain)
+		require.NotNil(t, stored)
+		require.NotNil(t, stored.ValidationExpiresAt)
+		assert.WithinDuration(t, *d.ValidationExpiresAt, *stored.ValidationExpiresAt, 0, "failed validation must not extend the deadline")
+	})
+}
+
+func TestCleanupExpiredDomains_Boundaries(t *testing.T) {
+	env := setupDomainTest(t)
+	events := captureDomainEvents(env)
+	ctx := context.Background()
+	now := time.Now().UTC().Truncate(time.Second)
+	tests := []struct {
+		name      string
+		expiresAt time.Time
+		validated bool
+		deleted   bool
+	}{
+		{"expired", now.Add(-time.Second), false, true},
+		{"deadline", now, false, true},
+		{"pending", now.Add(time.Second), false, false},
+		{"validated", now.Add(-time.Hour), true, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			d := createExpiringDomain(t, env, tt.name+".example.com", tt.expiresAt)
+			if tt.validated {
+				require.NoError(t, env.store.(*nbstore.SqlStore).GetDB().Model(d).Update("validated", true).Error)
+			}
+			env.manager.cleanupExpiredDomains(ctx, now)
+			stored := storedDomain(t, env.store, accountA, d.Domain)
+			if !tt.deleted {
+				assert.NotNil(t, stored, "pending and validated registrations must survive cleanup")
+				return
+			}
+			assert.Nil(t, stored, "expired unused registrations must be removed")
+			replacement, err := env.manager.CreateDomain(ctx, accountB, accountBUser, d.Domain, testCluster)
+			require.NoError(t, err)
+			assert.NotEqual(t, d.ID, replacement.ID, "the released name must receive a fresh registration")
+			assert.False(t, replacement.Validated, "the new account must validate its own registration")
+		})
+	}
+	got := events.get()
+	require.Len(t, got, 2, "only successful expiration deletions emit events")
+	for _, event := range got {
+		assert.Equal(t, activity.CustomDomainValidationExpired, event.Activity, "use the requested expiration event")
+		assert.Equal(t, activity.SystemInitiator, event.InitiatorID, "cleanup is attributed to the system")
+		assert.Equal(t, accountA, event.AccountID, "expiration belongs to the original account")
+		assert.NotEmpty(t, event.TargetID, "retain the deleted domain ID")
+		assert.NotEmpty(t, event.Meta["domain"], "retain the deleted domain name")
+		assert.NotEmpty(t, event.Meta["validation_expires_at"], "include the validation deadline")
+	}
+}
+
+func TestCleanupExpiredDomains_ContinuesPastProtectedBatch(t *testing.T) {
+	env := setupDomainTest(t)
+	ctx := context.Background()
+	now := time.Now().UTC()
+	for i := range validationCleanupBatch {
+		d := createExpiringDomain(t, env, fmt.Sprintf("protected-%d.example.com", i), now.Add(-time.Hour))
+		require.NoError(t, env.store.CreateService(ctx, &rpservice.Service{
+			ID: fmt.Sprintf("service-%d", i), AccountID: accountA, Domain: "app." + d.Domain,
+		}))
+	}
+	unprotected := createExpiringDomain(t, env, "unused.example.com", now.Add(-time.Hour))
+	env.manager.cleanupExpiredDomains(ctx, now)
+	assert.Nil(t, storedDomain(t, env.store, accountA, unprotected.Domain), "protected registrations must not starve later batches")
+	remaining, err := env.store.ListCustomDomains(ctx, accountA)
+	require.NoError(t, err)
+	assert.Len(t, remaining, validationCleanupBatch, "all registrations with dependent services must survive")
+}
+
+func TestCleanupExpiredDomains_ConcurrentWorkers(t *testing.T) {
+	env := setupDomainTest(t)
+	events := captureDomainEvents(env)
+	now := time.Now().UTC()
+	d := createExpiringDomain(t, env, "concurrent.example.com", now.Add(-time.Hour))
+	var workers sync.WaitGroup
+	for range 2 {
+		workers.Go(func() { env.manager.cleanupExpiredDomains(context.Background(), now) })
+	}
+	workers.Wait()
+	assert.Nil(t, storedDomain(t, env.store, accountA, d.Domain), "one worker must remove the expired registration")
+	assert.Len(t, events.get(), 1, "only the worker that deletes the row may emit the event")
+}
+
+func TestRunValidationCleanup_HourlyAndRestart(t *testing.T) {
+	env := setupClockDomainTest(t)
+	synctest.Test(t, func(t *testing.T) {
+		events := captureDomainEvents(env)
+		now := time.Now().UTC()
+		startup := createExpiringDomain(t, env, "startup.example.com", now.Add(-time.Hour))
+		hourly := createExpiringDomain(t, env, "hourly.example.com", now.Add(time.Minute))
+		ctx, cancel := context.WithCancel(context.Background())
+		done := make(chan struct{})
+		go func() {
+			defer close(done)
+			env.manager.RunValidationCleanup(ctx)
+		}()
+		synctest.Wait()
+		assert.Nil(t, storedDomain(t, env.store, accountA, startup.Domain), "startup must collect overdue registrations")
+		time.Sleep(59 * time.Minute)
+		synctest.Wait()
+		assert.NotNil(t, storedDomain(t, env.store, accountA, hourly.Domain), "cleanup must wait for the 60-minute interval")
+		time.Sleep(time.Minute)
+		synctest.Wait()
+		assert.Nil(t, storedDomain(t, env.store, accountA, hourly.Domain), "the hourly scan must collect expired registrations")
+		cancel()
+		<-done
+
+		offline := createExpiringDomain(t, env, "offline.example.com", time.Now().UTC().Add(time.Minute))
+		time.Sleep(2 * time.Hour)
+		assert.NotNil(t, storedDomain(t, env.store, accountA, offline.Domain), "a stopped worker must not continue deleting")
+		ctx, cancel = context.WithCancel(context.Background())
+		done = make(chan struct{})
+		go func() {
+			defer close(done)
+			env.manager.RunValidationCleanup(ctx)
+		}()
+		synctest.Wait()
+		assert.Nil(t, storedDomain(t, env.store, accountA, offline.Domain), "restart must use the persisted deadline")
+		cancel()
+		<-done
+		assert.Len(t, events.get(), 3, "each deletion should emit an expiration event")
+	})
+}
+
+type blockingDomainResolver struct {
+	started chan struct{}
+	release chan struct{}
+}
+
+func (r blockingDomainResolver) LookupCNAME(context.Context, string) (string, error) {
+	close(r.started)
+	<-r.release
+	return testCluster + ".", nil
+}
+
+func TestValidateDomain_DeadlinePassesDuringLookup(t *testing.T) {
+	for _, cleanup := range []bool{false, true} {
+		t.Run(fmt.Sprintf("cleanup=%t", cleanup), func(t *testing.T) {
+			env := setupClockDomainTest(t)
+			synctest.Test(t, func(t *testing.T) {
+				events := captureDomainEvents(env)
+				ctx := context.Background()
+				d, err := env.manager.CreateDomain(ctx, accountA, accountAUser, "late.example.com", testCluster)
+				require.NoError(t, err)
+				resolver := blockingDomainResolver{started: make(chan struct{}), release: make(chan struct{})}
+				env.manager.validator.Resolver = resolver
+				done := make(chan struct{})
+				go func() {
+					defer close(done)
+					env.manager.ValidateDomain(ctx, accountA, accountAUser, d.ID)
+				}()
+				<-resolver.started
+				time.Sleep(48 * time.Hour)
+				if cleanup {
+					env.manager.cleanupExpiredDomains(ctx, time.Now().UTC())
+					_, err = env.store.CreateCustomDomain(ctx, accountB, d.Domain, testCluster, false)
+					require.NoError(t, err)
+				}
+				close(resolver.release)
+				<-done
+				owner := accountA
+				if cleanup {
+					assert.Nil(t, storedDomain(t, env.store, accountA, d.Domain), "late validation must not restore the old claim")
+					owner = accountB
+				}
+				stored := storedDomain(t, env.store, owner, d.Domain)
+				require.NotNil(t, stored)
+				assert.False(t, stored.Validated, "late validation must not validate either claim")
+				for _, event := range events.get() {
+					assert.NotEqual(t, activity.DomainValidated, event.Activity, "a rejected write must not emit a validation event")
+				}
+			})
+		})
+	}
+}
+
+func setupClockDomainTest(t *testing.T) *domainTestEnv {
+	t.Helper()
+	// Network driver watchers cannot share cancellation channels across synctest bubbles.
+	// Store boundary and concurrency tests still exercise the selected database engine.
+	t.Setenv("NETBIRD_STORE_ENGINE", "sqlite")
+	return setupDomainTest(t)
+}
+
+func createExpiringDomain(t *testing.T, env *domainTestEnv, name string, expiresAt time.Time) *domain.Domain {
+	t.Helper()
+	d, err := env.store.CreateCustomDomain(context.Background(), accountA, name, testCluster, false)
+	require.NoError(t, err)
+	require.NoError(t, env.store.(*nbstore.SqlStore).GetDB().Model(d).Update("validation_expires_at", expiresAt).Error)
+	d.ValidationExpiresAt = &expiresAt
+	return d
+}
+
+type domainEvents struct {
+	mu     sync.Mutex
+	events []*activity.Event
+}
+
+func captureDomainEvents(env *domainTestEnv) *domainEvents {
+	events := &domainEvents{}
+	env.manager.accountManager = &mock_server.MockAccountManager{
+		StoreEventFunc: func(_ context.Context, initiator, target, account string, code activity.ActivityDescriber, meta map[string]any) {
+			if code == activity.DomainAdded {
+				return
+			}
+			events.mu.Lock()
+			defer events.mu.Unlock()
+			events.events = append(events.events, &activity.Event{
+				InitiatorID: initiator, TargetID: target, AccountID: account,
+				Activity: code.(activity.Activity), Meta: meta,
+			})
+		},
+	}
+	return events
+}
+
+func (e *domainEvents) get() []*activity.Event {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	return append([]*activity.Event(nil), e.events...)
+}
diff --git a/management/internals/modules/reverseproxy/domain/manager/manager.go b/management/internals/modules/reverseproxy/domain/manager/manager.go
index 46e4ced83..c0fb12e9c 100644
--- a/management/internals/modules/reverseproxy/domain/manager/manager.go
+++ b/management/internals/modules/reverseproxy/domain/manager/manager.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"net"
 	"strings"
+	"time"
 
 	log "github.com/sirupsen/logrus"
 
@@ -18,6 +19,7 @@ import (
 	"github.com/netbirdio/netbird/management/server/permissions/operations"
 	nbstore "github.com/netbirdio/netbird/management/server/store"
 	"github.com/netbirdio/netbird/management/server/types"
+	nbdomain "github.com/netbirdio/netbird/shared/management/domain"
 	"github.com/netbirdio/netbird/shared/management/status"
 )
 
@@ -32,6 +34,8 @@ type store interface {
 	CreateCustomDomain(ctx context.Context, accountID string, domainName string, targetCluster string, validated bool) (*domain.Domain, error)
 	UpdateCustomDomain(ctx context.Context, accountID string, d *domain.Domain) (*domain.Domain, error)
 	DeleteCustomDomain(ctx context.Context, accountID string, domainID string) error
+	GetExpiredCustomDomains(ctx context.Context, now time.Time, afterID domain.ID, limit int) ([]*domain.Domain, error)
+	DeleteExpiredCustomDomain(ctx context.Context, d *domain.Domain, now time.Time) (bool, error)
 }
 
 type proxyManager interface {
@@ -106,12 +110,13 @@ func (m Manager) GetDomains(ctx context.Context, accountID, userID string) ([]*d
 	// Add custom domains.
 	for _, d := range domains {
 		cd := &domain.Domain{
-			ID:            d.ID,
-			Domain:        d.Domain,
-			AccountID:     accountID,
-			TargetCluster: d.TargetCluster,
-			Type:          domain.TypeCustom,
-			Validated:     d.Validated,
+			ID:                  d.ID,
+			Domain:              d.Domain,
+			AccountID:           accountID,
+			TargetCluster:       d.TargetCluster,
+			Type:                domain.TypeCustom,
+			Validated:           d.Validated,
+			ValidationExpiresAt: d.ValidationExpiresAt,
 		}
 		if d.TargetCluster != "" {
 			cd.SupportsCustomPorts = m.proxyManager.ClusterSupportsCustomPorts(ctx, d.TargetCluster)
@@ -126,6 +131,7 @@ func (m Manager) GetDomains(ctx context.Context, accountID, userID string) ([]*d
 	return ret, nil
 }
 
+// CreateDomain registers a normalized custom domain and attempts DNS validation.
 func (m Manager) CreateDomain(ctx context.Context, accountID, userID, domainName, targetCluster string) (*domain.Domain, error) {
 	ok, ctx, err := m.permissionsManager.ValidateUserPermissions(ctx, accountID, userID, modules.Services, operations.Create)
 	if err != nil {
@@ -135,6 +141,15 @@ func (m Manager) CreateDomain(ctx context.Context, accountID, userID, domainName
 		return nil, status.NewPermissionDeniedError()
 	}
 
+	parsed, err := nbdomain.FromString(strings.TrimSuffix(domainName, "."))
+	if err != nil {
+		return nil, status.Errorf(status.InvalidArgument, "invalid domain: %v", err)
+	}
+	domainName = parsed.PunycodeString()
+	if !nbdomain.IsValidDomainNoWildcard(domainName) {
+		return nil, status.Errorf(status.InvalidArgument, "invalid domain format")
+	}
+
 	// Verify the target cluster is in the available clusters for this account
 	allowList, err := m.getClusterAllowList(ctx, accountID)
 	if err != nil {
@@ -243,6 +258,14 @@ func (m Manager) ValidateDomain(ctx context.Context, accountID, userID, domainID
 		}).WithError(err).Error("get custom domain from store")
 		return
 	}
+	if d.Validated {
+		return
+	}
+	if d.ValidationExpiresAt == nil || !time.Now().Before(*d.ValidationExpiresAt) {
+		log.WithFields(log.Fields{"accountID": accountID, "domainID": domainID}).
+			Debug("custom domain validation window has expired")
+		return
+	}
 
 	// Validate only against the domain's target cluster
 	targetCluster := d.TargetCluster
@@ -263,20 +286,21 @@ func (m Manager) ValidateDomain(ctx context.Context, accountID, userID, domainID
 	}).Info("validating domain against target cluster")
 
 	if m.validator.IsValid(context.Background(), d.Domain, []string{targetCluster}) {
-		log.WithFields(log.Fields{
-			"accountID": accountID,
-			"domainID":  domainID,
-			"domain":    d.Domain,
-		}).Info("domain validated successfully")
 		d.Validated = true
 		if _, err := m.store.UpdateCustomDomain(context.Background(), accountID, d); err != nil {
-			log.WithFields(log.Fields{
+			entry := log.WithFields(log.Fields{
 				"accountID": accountID,
 				"domainID":  domainID,
-				"domain":    d.Domain,
-			}).WithError(err).Error("update custom domain in store")
+			}).WithError(err)
+			if sErr, ok := status.FromError(err); ok && sErr.Type() == status.PreconditionFailed {
+				entry.Debug("custom domain registration is no longer pending validation")
+				return
+			}
+			entry.Error("update custom domain in store")
 			return
 		}
+		log.WithFields(log.Fields{"accountID": accountID, "domainID": domainID}).
+			Info("custom domain validated successfully")
 
 		m.accountManager.StoreEvent(context.Background(), userID, domainID, accountID, activity.DomainValidated, d.EventMeta())
 	} else {
diff --git a/management/internals/modules/reverseproxy/domain/manager/manager_realstore_test.go b/management/internals/modules/reverseproxy/domain/manager/manager_realstore_test.go
index 8a0b56171..5c973c40e 100644
--- a/management/internals/modules/reverseproxy/domain/manager/manager_realstore_test.go
+++ b/management/internals/modules/reverseproxy/domain/manager/manager_realstore_test.go
@@ -296,11 +296,8 @@ func TestValidateDomain_PermissionDeniedDoesNotValidate(t *testing.T) {
 	assert.Error(t, err, "the domain must still be unservable")
 }
 
-// Validation runs asynchronously, so it can finish after the domain was
-// deleted and then write a stale row back. gorm's Save falls back to an insert
-// when an update affects no rows, which would resurrect the domain as
-// validated; UpdateCustomDomain avoids that by selecting explicit columns.
-// This pins that behaviour, since dropping the Select would reintroduce it.
+// A validation finishing after deletion must reject the stale write, without
+// restoring the registration or reporting successful validation.
 func TestUpdateCustomDomain_DoesNotResurrectDeletedDomain(t *testing.T) {
 	ctx := context.Background()
 	env := setupDomainTest(t)
@@ -315,11 +312,9 @@ func TestUpdateCustomDomain_DoesNotResurrectDeletedDomain(t *testing.T) {
 	require.Nil(t, storedDomain(t, env.store, accountA, "racy.example.com"), "the domain should be gone")
 
 	// What an in-flight validation would write once its CNAME check succeeded.
-	// The write has to succeed for the assertion below to mean anything: a
-	// rejected write would leave the domain absent for the wrong reason.
 	stale.Validated = true
 	_, err = env.store.UpdateCustomDomain(ctx, accountA, stale)
-	require.NoError(t, err, "the update itself must succeed, so absence is not just a failed write")
+	require.Error(t, err, "a deleted registration must reject a late validation")
 
 	assert.Nil(t, storedDomain(t, env.store, accountA, "racy.example.com"),
 		"a late validation write must not recreate a deleted domain")
diff --git a/management/internals/modules/reverseproxy/domain/manager/manager_test.go b/management/internals/modules/reverseproxy/domain/manager/manager_test.go
index 519f5efeb..1ca690130 100644
--- a/management/internals/modules/reverseproxy/domain/manager/manager_test.go
+++ b/management/internals/modules/reverseproxy/domain/manager/manager_test.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -208,6 +209,14 @@ func (s *stubStore) DeleteCustomDomain(context.Context, string, string) error {
 	panic("not used in allow-list tests")
 }
 
+func (s *stubStore) GetExpiredCustomDomains(context.Context, time.Time, domain.ID, int) ([]*domain.Domain, error) {
+	panic("not used in allow-list tests")
+}
+
+func (s *stubStore) DeleteExpiredCustomDomain(context.Context, *domain.Domain, time.Time) (bool, error) {
+	panic("not used in allow-list tests")
+}
+
 // TestGetClusterAllowList_DedicatedGatewayAddressExcluded pins invariant (B)'s
 // chokepoint: a self-addressed settings pin reserves the account's gateway
 // address, so it is dropped from the allow list — which, because the
diff --git a/management/internals/modules/reverseproxy/domain/manager/normalization_test.go b/management/internals/modules/reverseproxy/domain/manager/normalization_test.go
new file mode 100644
index 000000000..da5e4bdd1
--- /dev/null
+++ b/management/internals/modules/reverseproxy/domain/manager/normalization_test.go
@@ -0,0 +1,83 @@
+package manager
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/shared/management/status"
+)
+
+func TestCreateDomain_NormalizesName(t *testing.T) {
+	for _, tt := range []struct {
+		name      string
+		input     string
+		canonical string
+	}{
+		{"mixed case", "Apps.Example.COM", "apps.example.com"},
+		{"unicode", "münchen.example.com", "xn--mnchen-3ya.example.com"},
+		{"trailing dot", "apps.example.com.", "apps.example.com"},
+		{"underscore", "My_App.example.com", "my_app.example.com"},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			ctx := context.Background()
+			env := setupDomainTest(t)
+			env.resolver.set("validation."+tt.canonical, testCluster)
+
+			created, err := env.manager.CreateDomain(ctx, accountA, accountAUser, tt.input, testCluster)
+			require.NoError(t, err)
+			assert.Equal(t, tt.canonical, created.Domain, "the response must use the normalized name")
+			assert.True(t, created.Validated, "the CNAME lookup must use the normalized name")
+			stored, err := env.store.GetCustomDomain(ctx, accountA, created.ID)
+			require.NoError(t, err)
+			assert.Equal(t, tt.canonical, stored.Domain, "the database must retain the normalized name")
+
+			_, err = env.manager.CreateDomain(ctx, accountB, accountBUser, tt.canonical, testCluster)
+			require.Error(t, err)
+			sErr, ok := status.FromError(err)
+			require.True(t, ok, "an equivalent name must return a typed conflict")
+			assert.Equal(t, status.AlreadyExists, sErr.Type(), "normalization must precede the availability check")
+		})
+	}
+}
+
+func TestCreateDomain_NormalizedNameCanValidateLater(t *testing.T) {
+	ctx := context.Background()
+	env := setupDomainTest(t)
+	created, err := env.manager.CreateDomain(ctx, accountA, accountAUser, "Apps.Example.COM.", testCluster)
+	require.NoError(t, err)
+	require.False(t, created.Validated, "a missing CNAME must leave the normalized registration pending")
+
+	env.resolver.set("validation.apps.example.com", testCluster)
+	env.manager.ValidateDomain(ctx, accountA, accountAUser, created.ID)
+	stored, err := env.store.GetCustomDomain(ctx, accountA, created.ID)
+	require.NoError(t, err)
+	assert.Equal(t, "apps.example.com", stored.Domain, "retrying validation must retain the normalized name")
+	assert.True(t, stored.Validated, "later validation must look up the normalized name")
+}
+
+func TestCreateDomain_RejectsInvalidName(t *testing.T) {
+	ctx := context.Background()
+	env := setupDomainTest(t)
+	for _, name := range []string{
+		"", ".", "app..example.com", "app.example.com..", "-app.example.com",
+		"app%.example.com", "app!.example.com", "*.example.com", "app example.com",
+		"https://example.com", strings.Repeat("a", 64) + ".example.com",
+	} {
+		t.Run(name, func(t *testing.T) {
+			// A matching DNS response must not make a malformed name acceptable.
+			env.resolver.set("validation."+name, testCluster)
+			_, err := env.manager.CreateDomain(ctx, accountA, accountAUser, name, testCluster)
+			require.Error(t, err)
+			sErr, ok := status.FromError(err)
+			require.True(t, ok, "invalid names must return a typed client error")
+			assert.Equal(t, status.InvalidArgument, sErr.Type(), "malformed names must be rejected before storage")
+		})
+	}
+	stored, err := env.store.ListCustomDomains(ctx, accountA)
+	require.NoError(t, err)
+	assert.Empty(t, stored, "invalid registration attempts must not reserve any names")
+}
diff --git a/management/internals/server/server.go b/management/internals/server/server.go
index 9709d1099..a1b58fdf1 100644
--- a/management/internals/server/server.go
+++ b/management/internals/server/server.go
@@ -66,7 +66,8 @@ type BaseServer struct {
 	disableLegacyManagementPort bool
 	autoResolveDomains          bool
 
-	proxyAuthClose func()
+	proxyAuthClose    func()
+	domainCleanupStop func()
 
 	// grpcExtensions holds additional gRPC services, interceptors, and shutdown
 	// hooks registered by external modules via RegisterGRPCExtension. Populated
@@ -227,9 +228,26 @@ func (s *BaseServer) Start(ctx context.Context) error {
 	s.update.SetOnUpdateListener(func() {
 		log.WithContext(ctx).Infof("your management version, \"%s\", is outdated, a new management version is available. Learn more here: https://github.com/netbirdio/netbird/releases", version.NetbirdVersion())
 	})
+	s.startDomainCleanup(srvCtx)
 
 	return nil
 }
+func (s *BaseServer) startDomainCleanup(ctx context.Context) {
+	if s.domainCleanupStop != nil {
+		return
+	}
+	mgr := s.ReverseProxyDomainManager()
+	ctx, cancel := context.WithCancel(ctx)
+	done := make(chan struct{})
+	s.domainCleanupStop = func() {
+		cancel()
+		<-done
+	}
+	go func() {
+		defer close(done)
+		mgr.RunValidationCleanup(ctx)
+	}()
+}
 
 // setupTLS resolves the listener's TLS source: an injected config wins over the HttpConfig certificate settings
 func (s *BaseServer) setupTLS(ctx context.Context) (bool, error) {
@@ -260,6 +278,9 @@ func (s *BaseServer) setupTLS(ctx context.Context) (bool, error) {
 func (s *BaseServer) Stop() error {
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancel()
+	if s.domainCleanupStop != nil {
+		s.domainCleanupStop()
+	}
 
 	s.IntegratedValidator().Stop(ctx)
 	if s.GeoLocationManager() != nil {
diff --git a/management/server/activity/codes.go b/management/server/activity/codes.go
index 4d50fee3e..dca043027 100644
--- a/management/server/activity/codes.go
+++ b/management/server/activity/codes.go
@@ -284,6 +284,9 @@ const (
 	// AgentNetworkSettingsDeleted indicates that a user deleted the Agent Network account settings, releasing the endpoint
 	AgentNetworkSettingsDeleted Activity = 142
 
+	// CustomDomainValidationExpired indicates that an unvalidated domain registration expired.
+	CustomDomainValidationExpired Activity = 143
+
 	AccountDeleted Activity = 99999
 )
 
@@ -461,9 +464,10 @@ var activityMap = map[Activity]Code{
 	AccountMetricsPushEnabled:  {"Account metrics push enabled", "account.setting.metrics.push.enable"},
 	AccountMetricsPushDisabled: {"Account metrics push disabled", "account.setting.metrics.push.disable"},
 
-	DomainAdded:     {"Domain added", "domain.add"},
-	DomainDeleted:   {"Domain deleted", "domain.delete"},
-	DomainValidated: {"Domain validated", "domain.validate"},
+	DomainAdded:                   {"Domain added", "domain.add"},
+	DomainDeleted:                 {"Domain deleted", "domain.delete"},
+	DomainValidated:               {"Domain validated", "domain.validate"},
+	CustomDomainValidationExpired: {"Unvalidated domain registration expired", "domain.validation.expire"},
 }
 
 // StringCode returns a string code of the activity
diff --git a/management/server/activity/store/sql_store.go b/management/server/activity/store/sql_store.go
index 73e8e295c..5b0f23dd0 100644
--- a/management/server/activity/store/sql_store.go
+++ b/management/server/activity/store/sql_store.go
@@ -165,16 +165,16 @@ func (store *Store) Get(ctx context.Context, accountID string, offset, limit int
 	return store.processResult(ctx, events)
 }
 
-// Save an event in the SQLite events table end encrypt the "email" element in meta map
-func (store *Store) Save(_ context.Context, event *activity.Event) (*activity.Event, error) {
+// Save persists an activity event and encrypts deleted user details using the caller's context.
+func (store *Store) Save(ctx context.Context, event *activity.Event) (*activity.Event, error) {
 	eventCopy := event.Copy()
-	meta, err := store.saveDeletedUserEmailAndNameInEncrypted(eventCopy)
+	meta, err := store.saveDeletedUserEmailAndNameInEncrypted(ctx, eventCopy)
 	if err != nil {
 		return nil, err
 	}
 	eventCopy.Meta = meta
 
-	if err = store.db.Create(eventCopy).Error; err != nil {
+	if err = store.db.WithContext(ctx).Create(eventCopy).Error; err != nil {
 		return nil, err
 	}
 
@@ -183,7 +183,7 @@ func (store *Store) Save(_ context.Context, event *activity.Event) (*activity.Ev
 
 // saveDeletedUserEmailAndNameInEncrypted if the meta contains email and name then store it in encrypted way and delete
 // this item from meta map
-func (store *Store) saveDeletedUserEmailAndNameInEncrypted(event *activity.Event) (map[string]any, error) {
+func (store *Store) saveDeletedUserEmailAndNameInEncrypted(ctx context.Context, event *activity.Event) (map[string]any, error) {
 	email, ok := event.Meta["email"]
 	if !ok {
 		return event.Meta, nil
@@ -211,7 +211,7 @@ func (store *Store) saveDeletedUserEmailAndNameInEncrypted(event *activity.Event
 	}
 	deletedUser.Name = encryptedName
 
-	err = store.db.Clauses(clause.OnConflict{
+	err = store.db.WithContext(ctx).Clauses(clause.OnConflict{
 		Columns:   []clause.Column{{Name: "id"}},
 		DoUpdates: clause.AssignmentColumns([]string{"email", "name"}),
 	}).Create(deletedUser).Error
diff --git a/management/server/activity/store/sql_store_test.go b/management/server/activity/store/sql_store_test.go
index d723f1623..0a68858e4 100644
--- a/management/server/activity/store/sql_store_test.go
+++ b/management/server/activity/store/sql_store_test.go
@@ -7,11 +7,49 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 
 	"github.com/netbirdio/netbird/management/server/activity"
 	"github.com/netbirdio/netbird/util/crypt"
 )
 
+func TestSave_CancellationWhileWaitingForConnection(t *testing.T) {
+	t.Setenv(storeEngineEnv, "sqlite")
+	key, err := crypt.GenerateKey()
+	require.NoError(t, err)
+	store, err := NewSqlStore(context.Background(), t.TempDir(), key)
+	require.NoError(t, err)
+	t.Cleanup(func() { assert.NoError(t, store.Close(context.Background())) })
+	db, err := store.db.DB()
+	require.NoError(t, err)
+	conn, err := db.Conn(context.Background())
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = conn.Close() })
+	ctx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond)
+	defer cancel()
+	result := make(chan error, 1)
+	go func() {
+		_, err := store.Save(ctx, &activity.Event{
+			Timestamp: time.Now().UTC(), Activity: activity.CustomDomainValidationExpired,
+			AccountID: "account-id", TargetID: "domain-id", InitiatorID: activity.SystemInitiator,
+		})
+		result <- err
+	}()
+	select {
+	case err := <-result:
+		assert.ErrorIs(t, err, context.DeadlineExceeded)
+		require.NoError(t, conn.Close())
+	case <-time.After(time.Second):
+		// Release the connection so a regression cannot leave the writer running.
+		require.NoError(t, conn.Close())
+		assert.ErrorIs(t, <-result, context.DeadlineExceeded)
+		t.Error("activity writes must stop waiting when their deadline expires")
+	}
+	events, err := store.Get(context.Background(), "account-id", 0, 10, true)
+	require.NoError(t, err)
+	assert.Empty(t, events, "a timed-out write must not persist after the connection is released")
+}
+
 func TestNewSqlStore(t *testing.T) {
 	dataDir := t.TempDir()
 	key, _ := crypt.GenerateKey()
diff --git a/management/server/event.go b/management/server/event.go
index 4211f2dda..2b1ac4987 100644
--- a/management/server/event.go
+++ b/management/server/event.go
@@ -61,23 +61,34 @@ func (am *DefaultAccountManager) GetEvents(ctx context.Context, accountID, userI
 	return filtered, nil
 }
 
+// StoreEvent records an activity, waiting for expiration events before cleanup can stop.
 func (am *DefaultAccountManager) StoreEvent(ctx context.Context, initiatorID, targetID, accountID string, activityID activity.ActivityDescriber, meta map[string]any) {
-	if isEnabled() {
-		go func() {
-			_, err := am.eventStore.Save(ctx, &activity.Event{
-				Timestamp:   time.Now().UTC(),
-				Activity:    activityID.(activity.Activity),
-				InitiatorID: initiatorID,
-				TargetID:    targetID,
-				AccountID:   accountID,
-				Meta:        meta,
-			})
-			if err != nil {
-				// todo add metric
-				log.WithContext(ctx).Errorf("received an error while storing an activity event, error: %s", err)
-			}
-		}()
+	if !isEnabled() {
+		return
 	}
+	eventStore := am.eventStore
+	save := func(ctx context.Context) {
+		_, err := eventStore.Save(ctx, &activity.Event{
+			Timestamp:   time.Now().UTC(),
+			Activity:    activityID.(activity.Activity),
+			InitiatorID: initiatorID,
+			TargetID:    targetID,
+			AccountID:   accountID,
+			Meta:        meta,
+		})
+		if err != nil {
+			log.WithContext(ctx).Errorf("received an error while storing an activity event, error: %s", err)
+		}
+	}
+	if activityID == activity.CustomDomainValidationExpired {
+		// The domain is already deleted; shutdown must allow its audit write to finish.
+		ctx, cancel := context.WithTimeout(context.WithoutCancel(ctx), 5*time.Second)
+		defer cancel()
+		save(ctx)
+		return
+	}
+	// Request cancellation must not discard the audit record of a completed operation.
+	go save(context.WithoutCancel(ctx))
 }
 
 type eventUserInfo struct {
diff --git a/management/server/event_test.go b/management/server/event_test.go
index 420e69866..6fb3f437f 100644
--- a/management/server/event_test.go
+++ b/management/server/event_test.go
@@ -6,10 +6,52 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 
 	"github.com/netbirdio/netbird/management/server/activity"
+	activitystore "github.com/netbirdio/netbird/management/server/activity/store"
+	"github.com/netbirdio/netbird/util/crypt"
 )
 
+func TestStoreEvent_CanceledContext(t *testing.T) {
+	t.Setenv("NB_EVENT_ACTIVITY_LOG_ENABLED", "true")
+	t.Setenv("NB_ACTIVITY_EVENT_STORE_ENGINE", "sqlite")
+	for _, code := range []activity.Activity{activity.CustomDomainValidationExpired, activity.DomainAdded} {
+		t.Run(code.StringCode(), func(t *testing.T) {
+			dir := t.TempDir()
+			key, err := crypt.GenerateKey()
+			require.NoError(t, err)
+			eventStore, err := activitystore.NewSqlStore(context.Background(), dir, key)
+			require.NoError(t, err)
+			t.Cleanup(func() { assert.NoError(t, eventStore.Close(context.Background())) })
+			manager := &DefaultAccountManager{eventStore: eventStore}
+			ctx, cancel := context.WithCancel(context.Background())
+			cancel()
+
+			// The operation already succeeded when shutdown or the request cancels its context.
+			manager.StoreEvent(ctx, activity.SystemInitiator, "domain-id", "account-id",
+				code, map[string]any{"domain": "expired.example.com"})
+			if code != activity.CustomDomainValidationExpired {
+				require.Eventually(t, func() bool {
+					events, err := eventStore.Get(context.Background(), "account-id", 0, 10, true)
+					return err == nil && len(events) == 1
+				}, time.Second, time.Millisecond, "asynchronous events must survive request cancellation")
+			}
+			require.NoError(t, eventStore.Close(context.Background()))
+
+			reopened, err := activitystore.NewSqlStore(context.Background(), dir, key)
+			require.NoError(t, err)
+			t.Cleanup(func() { assert.NoError(t, reopened.Close(context.Background())) })
+			events, err := reopened.Get(context.Background(), "account-id", 0, 10, true)
+			require.NoError(t, err)
+			require.Len(t, events, 1, "the event must be persisted before shutdown closes the store")
+			assert.Equal(t, code, events[0].Activity, "persist the requested activity")
+			assert.Equal(t, "domain-id", events[0].TargetID, "retain the registration ID")
+			assert.Equal(t, "expired.example.com", events[0].Meta["domain"], "retain the domain name")
+		})
+	}
+}
+
 func generateAndStoreEvents(t *testing.T, manager *DefaultAccountManager, typ activity.Activity, initiatorID, targetID,
 	accountID string, count int) {
 	t.Helper()
diff --git a/management/server/http/testing/integration/events_handler_integration_test.go b/management/server/http/testing/integration/events_handler_integration_test.go
index 6611b60ee..a051aabcd 100644
--- a/management/server/http/testing/integration/events_handler_integration_test.go
+++ b/management/server/http/testing/integration/events_handler_integration_test.go
@@ -3,6 +3,7 @@
 package integration
 
 import (
+	"context"
 	"encoding/json"
 	"net/http"
 	"net/http/httptest"
@@ -10,6 +11,7 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 
 	"github.com/netbirdio/netbird/management/server/http/testing/testing_tools"
 	"github.com/netbirdio/netbird/management/server/http/testing/testing_tools/channel"
@@ -34,7 +36,7 @@ func Test_Events_GetAll(t *testing.T) {
 
 	for _, user := range users {
 		t.Run(user.name+" - Get all events", func(t *testing.T) {
-			apiHandler, _, _ := channel.BuildApiBlackBoxWithDBState(t, "../testdata/events.sql", nil, false)
+			apiHandler, accountManager, _ := channel.BuildApiBlackBoxWithDBState(t, "../testdata/events.sql", nil, false)
 
 			// First, perform a mutation to generate an event (create a group as admin)
 			groupBody, err := json.Marshal(&api.GroupRequest{Name: "eventTestGroup"})
@@ -44,7 +46,14 @@ func Test_Events_GetAll(t *testing.T) {
 			createReq := testing_tools.BuildRequest(t, groupBody, http.MethodPost, "/api/groups", testing_tools.TestAdminId)
 			createRecorder := httptest.NewRecorder()
 			apiHandler.ServeHTTP(createRecorder, createReq)
-			assert.Equal(t, http.StatusOK, createRecorder.Code, "Failed to create group to generate event")
+			require.Equal(t, http.StatusOK, createRecorder.Code, "Failed to create group to generate event")
+
+			// Group creation returns before its asynchronous audit write finishes.
+			require.EventuallyWithT(t, func(c *assert.CollectT) {
+				events, err := accountManager.GetEvents(context.Background(), testing_tools.TestAccountId, testing_tools.TestAdminId)
+				assert.NoError(c, err)
+				assert.NotEmpty(c, events, "wait for the group creation event before checking permissions")
+			}, time.Second, 10*time.Millisecond)
 
 			// Now query events
 			req := testing_tools.BuildRequest(t, []byte{}, http.MethodGet, "/api/events", user.userId)
diff --git a/management/server/migration/migration_custom_domain.go b/management/server/migration/migration_custom_domain.go
new file mode 100644
index 000000000..bac784358
--- /dev/null
+++ b/management/server/migration/migration_custom_domain.go
@@ -0,0 +1,22 @@
+package migration
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"gorm.io/gorm"
+
+	"github.com/netbirdio/netbird/management/internals/modules/reverseproxy/domain"
+)
+
+// MigrateCustomDomainValidationExpiry gives existing pending registrations a validation window.
+func MigrateCustomDomainValidationExpiry(ctx context.Context, db *gorm.DB) error {
+	result := db.WithContext(ctx).Model(&domain.Domain{}).
+		Where("validated = ? AND validation_expires_at IS NULL", false).
+		Update("validation_expires_at", time.Now().UTC().Add(domain.ValidationTTL))
+	if result.Error != nil {
+		return fmt.Errorf("backfill custom domain validation expiry: %w", result.Error)
+	}
+	return nil
+}
diff --git a/management/server/migration/migration_custom_domain_test.go b/management/server/migration/migration_custom_domain_test.go
new file mode 100644
index 000000000..facf23c9f
--- /dev/null
+++ b/management/server/migration/migration_custom_domain_test.go
@@ -0,0 +1,44 @@
+package migration_test
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/management/internals/modules/reverseproxy/domain"
+	"github.com/netbirdio/netbird/management/server/migration"
+)
+
+func TestMigrateCustomDomainValidationExpiry(t *testing.T) {
+	db := setupDatabase(t)
+	require.NoError(t, db.AutoMigrate(&domain.Domain{}))
+	t.Cleanup(func() { require.NoError(t, db.Migrator().DropTable(&domain.Domain{})) })
+	ctx := context.Background()
+	existingDeadline := time.Now().UTC().Add(time.Hour).Truncate(time.Second)
+	rows := []domain.Domain{
+		{ID: "legacy", Domain: "legacy.example.com"},
+		{ID: "validated", Domain: "validated.example.com", Validated: true},
+		{ID: "pending", Domain: "pending.example.com", ValidationExpiresAt: &existingDeadline},
+	}
+	require.NoError(t, db.Create(&rows).Error)
+	before := time.Now().UTC()
+	require.NoError(t, migration.MigrateCustomDomainValidationExpiry(ctx, db))
+	after := time.Now().UTC()
+	var migrated domain.Domain
+	require.NoError(t, db.First(&migrated, "id = ?", "legacy").Error)
+	require.NotNil(t, migrated.ValidationExpiresAt)
+	assert.WithinRange(t, *migrated.ValidationExpiresAt, before.Truncate(time.Millisecond).Add(48*time.Hour), after.Add(48*time.Hour+time.Millisecond), "legacy pending registrations get a full window")
+	deadline := *migrated.ValidationExpiresAt
+	require.NoError(t, migration.MigrateCustomDomainValidationExpiry(ctx, db))
+	require.NoError(t, db.First(&migrated, "id = ?", "legacy").Error)
+	assert.Equal(t, deadline, *migrated.ValidationExpiresAt, "repeated migration must not extend the deadline")
+	var validated, pending domain.Domain
+	require.NoError(t, db.First(&validated, "id = ?", "validated").Error)
+	require.NoError(t, db.First(&pending, "id = ?", "pending").Error)
+	assert.Nil(t, validated.ValidationExpiresAt, "validated domains do not acquire an expiry")
+	require.NotNil(t, pending.ValidationExpiresAt)
+	assert.WithinDuration(t, existingDeadline, *pending.ValidationExpiresAt, 0, "existing deadlines must be preserved")
+}
diff --git a/management/server/store/sql_store.go b/management/server/store/sql_store.go
index 33c723a8a..08ec45395 100644
--- a/management/server/store/sql_store.go
+++ b/management/server/store/sql_store.go
@@ -5712,6 +5712,10 @@ func (s *SqlStore) CreateCustomDomain(ctx context.Context, accountID string, dom
 		Type:          domain.TypeCustom,
 		Validated:     validated,
 	}
+	if !validated {
+		expiresAt := time.Now().UTC().Add(domain.ValidationTTL)
+		newDomain.ValidationExpiresAt = &expiresAt
+	}
 	result := s.db.Create(newDomain)
 	if result.Error != nil {
 		// The unique index is the last guard when two requests clear the
@@ -5733,12 +5737,21 @@ func (s *SqlStore) CreateCustomDomain(ctx context.Context, accountID string, dom
 	return newDomain, nil
 }
 
+// UpdateCustomDomain completes validation only while the original registration is pending.
 func (s *SqlStore) UpdateCustomDomain(ctx context.Context, accountID string, d *domain.Domain) (*domain.Domain, error) {
-	d.AccountID = accountID
-	result := s.db.Select("*").Save(d)
+	if !d.Validated {
+		return nil, status.Errorf(status.InvalidArgument, "custom domain update must complete validation")
+	}
+	result := s.db.WithContext(ctx).Model(&domain.Domain{}).
+		Where(accountAndIDQueryCondition, accountID, d.ID).
+		Where("domain = ? AND target_cluster = ?", d.Domain, d.TargetCluster).
+		Where("validated = ? AND validation_expires_at > ?", false, time.Now().UTC()).
+		Update("validated", true)
 	if result.Error != nil {
-		log.WithContext(ctx).Errorf("failed to update reverse proxy custom domain to store: %v", result.Error)
-		return nil, status.Errorf(status.Internal, "failed to update reverse proxy custom domain to store")
+		return nil, fmt.Errorf("validate custom domain in store: %w", result.Error)
+	}
+	if result.RowsAffected == 0 {
+		return nil, status.Errorf(status.PreconditionFailed, "custom domain registration is no longer pending validation")
 	}
 
 	return d, nil
diff --git a/management/server/store/sql_store_domain_expiration.go b/management/server/store/sql_store_domain_expiration.go
new file mode 100644
index 000000000..525c54084
--- /dev/null
+++ b/management/server/store/sql_store_domain_expiration.go
@@ -0,0 +1,60 @@
+package store
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"time"
+
+	"gorm.io/gorm"
+
+	"github.com/netbirdio/netbird/management/internals/modules/reverseproxy/domain"
+	rpservice "github.com/netbirdio/netbird/management/internals/modules/reverseproxy/service"
+	"github.com/netbirdio/netbird/shared/management/status"
+)
+
+// GetExpiredCustomDomains lists pending registrations in stable batches across accounts.
+func (s *SqlStore) GetExpiredCustomDomains(ctx context.Context, now time.Time, afterID domain.ID, limit int) ([]*domain.Domain, error) {
+	var domains []*domain.Domain
+	result := s.db.WithContext(ctx).
+		Where("validated = ? AND validation_expires_at <= ? AND id > ?", false, now, string(afterID)).
+		Order("id").Limit(limit).Find(&domains)
+	if result.Error != nil {
+		return nil, fmt.Errorf("list expired custom domains: %w", result.Error)
+	}
+	return domains, nil
+}
+
+// DeleteExpiredCustomDomain deletes an expired registration only if no service uses its namespace.
+func (s *SqlStore) DeleteExpiredCustomDomain(ctx context.Context, d *domain.Domain, now time.Time) (bool, error) {
+	db := s.db.WithContext(ctx)
+	services := customDomainServices(db, d)
+	result := db.Where(accountAndIDQueryCondition, d.AccountID, d.ID).
+		Where("domain = ? AND validated = ? AND validation_expires_at <= ?", d.Domain, false, now).
+		Where("NOT EXISTS (?)", services.Select("1")).Delete(&domain.Domain{})
+	if result.Error != nil {
+		return false, fmt.Errorf("delete expired custom domain: %w", result.Error)
+	}
+	if result.RowsAffected > 0 {
+		return true, nil
+	}
+	var count int64
+	if err := customDomainServices(db, d).Count(&count).Error; err != nil {
+		return false, fmt.Errorf("check expired custom domain services: %w", err)
+	}
+	if count > 0 {
+		return false, status.Errorf(status.PreconditionFailed, "expired custom domain still has dependent services")
+	}
+	return false, nil
+}
+
+func customDomainServices(db *gorm.DB, d *domain.Domain) *gorm.DB {
+	name := strings.ToLower(strings.TrimSuffix(d.Domain, "."))
+	// Shared domain validation permits underscores, and older rows may contain
+	// other LIKE metacharacters.
+	escaped := strings.NewReplacer("!", "!!", "%", "!%", "_", "!_").Replace(name)
+	return db.Model(&rpservice.Service{}).Where(
+		"LOWER(domain) IN ? OR LOWER(domain) LIKE ? ESCAPE '!' OR LOWER(domain) LIKE ? ESCAPE '!'",
+		[]string{name, name + "."}, "%."+escaped, "%."+escaped+".",
+	)
+}
diff --git a/management/server/store/sql_store_domain_expiration_test.go b/management/server/store/sql_store_domain_expiration_test.go
new file mode 100644
index 000000000..7dcfb0562
--- /dev/null
+++ b/management/server/store/sql_store_domain_expiration_test.go
@@ -0,0 +1,78 @@
+package store
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/management/internals/modules/reverseproxy/domain"
+	rpservice "github.com/netbirdio/netbird/management/internals/modules/reverseproxy/service"
+)
+
+func TestDeleteExpiredCustomDomain_ServiceDependencies(t *testing.T) {
+	runTestForAllEngines(t, "", func(t *testing.T, store Store) {
+		ctx := context.Background()
+		now := time.Now().UTC()
+		db := store.(*SqlStore).db
+		require.NoError(t, store.SaveAccount(ctx, newAccountWithId(ctx, "owner", "admin", "")))
+		for _, tt := range []struct {
+			name        string
+			domainName  string
+			serviceHost string
+			protected   bool
+		}{
+			{"exact", "example.com", "example.com", true},
+			{"subdomain", "example.com", "deep.app.example.com", true},
+			{"case", "example.com", "APP.EXAMPLE.COM.", true},
+			{"suffix-boundary", "example.com", "notexample.com", false},
+			{"literal underscore", "a_b.example.com", "app.a_b.example.com", true},
+			{"underscore wildcard", "a_b.example.com", "app.axb.example.com", false},
+			{"legacy percent wildcard", "a%b.example.com", "app.axxb.example.com", false},
+			{"legacy escape character", "a!b.example.com", "app.ab.example.com", false},
+		} {
+			t.Run(tt.name, func(t *testing.T) {
+				d, err := store.CreateCustomDomain(ctx, "owner", tt.domainName, "cluster", false)
+				require.NoError(t, err)
+				require.NoError(t, db.Model(d).Update("validation_expires_at", now.Add(-time.Hour)).Error)
+				svc := &rpservice.Service{ID: "legacy", AccountID: "owner", Domain: tt.serviceHost}
+				require.NoError(t, store.CreateService(ctx, svc))
+				deleted, err := store.DeleteExpiredCustomDomain(ctx, d, now)
+				if tt.protected {
+					require.Error(t, err)
+					assert.False(t, deleted, "service namespaces must remain reserved")
+				} else {
+					require.NoError(t, err)
+					assert.True(t, deleted, "a hostname outside the namespace must not prevent cleanup")
+				}
+				require.NoError(t, db.Delete(svc).Error)
+				require.NoError(t, db.Delete(d).Error)
+			})
+		}
+	})
+}
+
+func TestDeleteExpiredCustomDomain_RechecksValidation(t *testing.T) {
+	runTestForAllEngines(t, "", func(t *testing.T, store Store) {
+		ctx := context.Background()
+		require.NoError(t, store.SaveAccount(ctx, newAccountWithId(ctx, "owner", "admin", "")))
+		d, err := store.CreateCustomDomain(ctx, "owner", "validated.example.com", "cluster", false)
+		require.NoError(t, err)
+		d, err = store.GetCustomDomain(ctx, "owner", d.ID)
+		require.NoError(t, err)
+		stale := d.Copy()
+		d.Validated = true
+		_, err = store.UpdateCustomDomain(ctx, "owner", d)
+		require.NoError(t, err)
+		deleted, err := store.DeleteExpiredCustomDomain(ctx, stale, time.Now().Add(domain.ValidationTTL))
+		require.NoError(t, err)
+		assert.False(t, deleted, "a stale cleanup candidate must not delete a validated registration")
+		stored, err := store.GetCustomDomain(ctx, "owner", d.ID)
+		require.NoError(t, err)
+		assert.True(t, stored.Validated, "the validated registration must remain usable")
+		require.NotNil(t, stored.ValidationExpiresAt)
+		assert.Equal(t, stale.ValidationExpiresAt, stored.ValidationExpiresAt, "validation must preserve the original deadline")
+	})
+}
diff --git a/management/server/store/sql_store_get_account_test.go b/management/server/store/sql_store_get_account_test.go
index 686839b1f..aca8d8a12 100644
--- a/management/server/store/sql_store_get_account_test.go
+++ b/management/server/store/sql_store_get_account_test.go
@@ -64,7 +64,7 @@ func assertGetAccountLoadsCustomDomains(t *testing.T, store Store) {
 
 	_, err := store.CreateCustomDomain(ctx, accountID, "example.com", "eu.proxy.netbird.io", true)
 	require.NoError(t, err, "creating the first custom domain must succeed")
-	_, err = store.CreateCustomDomain(ctx, accountID, "apps.acme.io", "us.proxy.netbird.io", false)
+	pending, err := store.CreateCustomDomain(ctx, accountID, "apps.acme.io", "us.proxy.netbird.io", false)
 	require.NoError(t, err, "creating the second custom domain must succeed")
 
 	account, err := store.GetAccount(ctx, accountID)
@@ -75,6 +75,10 @@ func assertGetAccountLoadsCustomDomains(t *testing.T, store Store) {
 	for _, d := range account.Domains {
 		require.NotNil(t, d)
 		byDomain[d.Domain] = d.TargetCluster
+		if d.ID == pending.ID {
+			require.NotNil(t, d.ValidationExpiresAt)
+			assert.WithinDuration(t, *pending.ValidationExpiresAt, *d.ValidationExpiresAt, time.Millisecond, "both account loaders must preserve the validation deadline")
+		}
 	}
 	assert.Equal(t, "eu.proxy.netbird.io", byDomain["example.com"], "custom domain must carry its target cluster")
 	assert.Equal(t, "us.proxy.netbird.io", byDomain["apps.acme.io"], "custom domain must carry its target cluster")
diff --git a/management/server/store/store.go b/management/server/store/store.go
index da2b3c6e0..6886536b9 100644
--- a/management/server/store/store.go
+++ b/management/server/store/store.go
@@ -305,6 +305,8 @@ type Store interface {
 	GetCustomDomainByName(ctx context.Context, domainName string) (*domain.Domain, error)
 	CreateCustomDomain(ctx context.Context, accountID string, domainName string, targetCluster string, validated bool) (*domain.Domain, error)
 	UpdateCustomDomain(ctx context.Context, accountID string, d *domain.Domain) (*domain.Domain, error)
+	GetExpiredCustomDomains(ctx context.Context, now time.Time, afterID domain.ID, limit int) ([]*domain.Domain, error)
+	DeleteExpiredCustomDomain(ctx context.Context, d *domain.Domain, now time.Time) (bool, error)
 	DeleteCustomDomain(ctx context.Context, accountID string, domainID string) error
 
 	CreateAccessLog(ctx context.Context, log *accesslogs.AccessLogEntry) error
@@ -642,6 +644,9 @@ func migratePostAuto(ctx context.Context, db *gorm.DB) error {
 
 func getMigrationsPostAuto(ctx context.Context) []migrationFunc {
 	return []migrationFunc{
+		func(db *gorm.DB) error {
+			return migration.MigrateCustomDomainValidationExpiry(ctx, db)
+		},
 		func(db *gorm.DB) error {
 			return migration.CreateIndexIfNotExists[nbpeer.Peer](ctx, db, "idx_account_ip", "account_id", "ip")
 		},
diff --git a/management/server/store/store_mock.go b/management/server/store/store_mock.go
index 9bf49f076..04f79d30a 100644
--- a/management/server/store/store_mock.go
+++ b/management/server/store/store_mock.go
@@ -555,6 +555,21 @@ func (mr *MockStoreMockRecorder) DeleteDNSRecord(ctx, accountID, zoneID, recordI
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "DeleteDNSRecord", reflect.TypeOf((*MockStore)(nil).DeleteDNSRecord), ctx, accountID, zoneID, recordID)
 }
 
+// DeleteExpiredCustomDomain mocks base method.
+func (m *MockStore) DeleteExpiredCustomDomain(ctx context.Context, d *domain.Domain, now time.Time) (bool, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "DeleteExpiredCustomDomain", ctx, d, now)
+	ret0, _ := ret[0].(bool)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// DeleteExpiredCustomDomain indicates an expected call of DeleteExpiredCustomDomain.
+func (mr *MockStoreMockRecorder) DeleteExpiredCustomDomain(ctx, d, now any) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "DeleteExpiredCustomDomain", reflect.TypeOf((*MockStore)(nil).DeleteExpiredCustomDomain), ctx, d, now)
+}
+
 // DeleteGroup mocks base method.
 func (m *MockStore) DeleteGroup(ctx context.Context, accountID, groupID string) error {
 	m.ctrl.T.Helper()
@@ -2002,6 +2017,21 @@ func (mr *MockStoreMockRecorder) GetEmbeddedProxyPeerIDsByCluster(ctx, accountID
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetEmbeddedProxyPeerIDsByCluster", reflect.TypeOf((*MockStore)(nil).GetEmbeddedProxyPeerIDsByCluster), ctx, accountID)
 }
 
+// GetExpiredCustomDomains mocks base method.
+func (m *MockStore) GetExpiredCustomDomains(ctx context.Context, now time.Time, afterID domain.ID, limit int) ([]*domain.Domain, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "GetExpiredCustomDomains", ctx, now, afterID, limit)
+	ret0, _ := ret[0].([]*domain.Domain)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// GetExpiredCustomDomains indicates an expected call of GetExpiredCustomDomains.
+func (mr *MockStoreMockRecorder) GetExpiredCustomDomains(ctx, now, afterID, limit any) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetExpiredCustomDomains", reflect.TypeOf((*MockStore)(nil).GetExpiredCustomDomains), ctx, now, afterID, limit)
+}
+
 // GetExpiredEphemeralServices mocks base method.
 func (m *MockStore) GetExpiredEphemeralServices(ctx context.Context, ttl time.Duration, limit int) ([]*service.Service, error) {
 	m.ctrl.T.Helper()