diff --git a/cmd/start/start.go b/cmd/start/start.go
index e671aadf1..a19bec304 100644
--- a/cmd/start/start.go
+++ b/cmd/start/start.go
@@ -360,7 +360,7 @@ func startAPIs(
 		http_util.WithMaxAge(int(math.Floor(config.Quotas.Access.ExhaustedCookieMaxAge.Seconds()))),
 	)
 	limitingAccessInterceptor := middleware.NewAccessInterceptor(accessSvc, exhaustedCookieHandler, &config.Quotas.Access.AccessConfig)
-	apis, err := api.New(ctx, config.Port, router, queries, verifier, config.InternalAuthZ, tlsConfig, config.HTTP2HostHeader, config.HTTP1HostHeader, limitingAccessInterceptor)
+	apis, err := api.New(ctx, config.Port, router, queries, verifier, config.InternalAuthZ, tlsConfig, config.HTTP2HostHeader, config.HTTP1HostHeader, config.ExternalDomain, limitingAccessInterceptor)
 	if err != nil {
 		return nil, fmt.Errorf("error creating api %w", err)
 	}
@@ -410,7 +410,7 @@ func startAPIs(
 	if err := apis.RegisterService(ctx, execution_v3_alpha.CreateServer(commands, queries, domain.AllFunctions, apis.ListGrpcMethods, apis.ListGrpcServices)); err != nil {
 		return nil, err
 	}
-	instanceInterceptor := middleware.InstanceInterceptor(queries, config.HTTP1HostHeader, login.IgnoreInstanceEndpoints...)
+	instanceInterceptor := middleware.InstanceInterceptor(queries, config.HTTP1HostHeader, config.ExternalDomain, login.IgnoreInstanceEndpoints...)
 	assetsCache := middleware.AssetsCacheInterceptor(config.AssetStorage.Cache.MaxAge, config.AssetStorage.Cache.SharedMaxAge)
 	apis.RegisterHandlerOnPrefix(assets.HandlerPrefix, assets.NewHandler(commands, verifier, config.InternalAuthZ, id.SonyFlakeGenerator(), store, queries, middleware.CallDurationHandler, instanceInterceptor.Handler, assetsCache.Handler, limitingAccessInterceptor.Handle))
 
diff --git a/docs/docs/apis/introduction.mdx b/docs/docs/apis/introduction.mdx
index 7ad38525b..7502b20be 100644
--- a/docs/docs/apis/introduction.mdx
+++ b/docs/docs/apis/introduction.mdx
@@ -268,6 +268,8 @@ ZITADEL hosts everything under a single domain: `{instance}.zitadel.cloud` or yo
 
 The domain is used as the OIDC issuer and as the base url for the gRPC and REST APIs, the Login and Console UI, which you'll find under `{your_domain}/ui/console/`.
 
+Are you self-hosting and having troubles with *Instance not found* errors? [Check out this page](https://zitadel.com/docs/self-hosting/manage/custom-domain).
+
 ## API path prefixes
 
 If you run ZITADEL on a custom domain, you may want to reuse that domain for other applications.
diff --git a/internal/api/api.go b/internal/api/api.go
index c4ae07f3f..2b94e1e28 100644
--- a/internal/api/api.go
+++ b/internal/api/api.go
@@ -74,7 +74,8 @@ func New(
 	queries *query.Queries,
 	verifier internal_authz.APITokenVerifier,
 	authZ internal_authz.Config,
-	tlsConfig *tls.Config, http2HostName, http1HostName string,
+	tlsConfig *tls.Config,
+	http2HostName, http1HostName, externalDomain string,
 	accessInterceptor *http_mw.AccessInterceptor,
 ) (_ *API, err error) {
 	api := &API{
@@ -87,7 +88,7 @@ func New(
 		accessInterceptor: accessInterceptor,
 	}
 
-	api.grpcServer = server.CreateServer(api.verifier, authZ, queries, http2HostName, tlsConfig, accessInterceptor.AccessService())
+	api.grpcServer = server.CreateServer(api.verifier, authZ, queries, http2HostName, externalDomain, tlsConfig, accessInterceptor.AccessService())
 	api.grpcGateway, err = server.CreateGateway(ctx, port, http1HostName, accessInterceptor, tlsConfig)
 	if err != nil {
 		return nil, err
diff --git a/internal/api/grpc/server/middleware/instance_interceptor.go b/internal/api/grpc/server/middleware/instance_interceptor.go
index 31f5e2c16..f5965beb3 100644
--- a/internal/api/grpc/server/middleware/instance_interceptor.go
+++ b/internal/api/grpc/server/middleware/instance_interceptor.go
@@ -14,6 +14,7 @@ import (
 	"google.golang.org/grpc/status"
 
 	"github.com/zitadel/zitadel/internal/api/authz"
+	zitadel_http "github.com/zitadel/zitadel/internal/api/http"
 	"github.com/zitadel/zitadel/internal/i18n"
 	"github.com/zitadel/zitadel/internal/telemetry/tracing"
 	"github.com/zitadel/zitadel/internal/zerrors"
@@ -23,15 +24,15 @@ const (
 	HTTP1Host = "x-zitadel-http1-host"
 )
 
-func InstanceInterceptor(verifier authz.InstanceVerifier, headerName string, explicitInstanceIdServices ...string) grpc.UnaryServerInterceptor {
+func InstanceInterceptor(verifier authz.InstanceVerifier, headerName, externalDomain string, explicitInstanceIdServices ...string) grpc.UnaryServerInterceptor {
 	translator, err := i18n.NewZitadelTranslator(language.English)
 	logging.OnError(err).Panic("unable to get translator")
 	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
-		return setInstance(ctx, req, info, handler, verifier, headerName, translator, explicitInstanceIdServices...)
+		return setInstance(ctx, req, info, handler, verifier, headerName, externalDomain, translator, explicitInstanceIdServices...)
 	}
 }
 
-func setInstance(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler, verifier authz.InstanceVerifier, headerName string, translator *i18n.Translator, idFromRequestsServices ...string) (_ interface{}, err error) {
+func setInstance(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler, verifier authz.InstanceVerifier, headerName, externalDomain string, translator *i18n.Translator, idFromRequestsServices ...string) (_ interface{}, err error) {
 	interceptorCtx, span := tracing.NewServerInterceptorSpan(ctx)
 	defer func() { span.EndWithError(err) }()
 	for _, service := range idFromRequestsServices {
@@ -55,16 +56,18 @@ func setInstance(ctx context.Context, req interface{}, info *grpc.UnaryServerInf
 			return handler(authz.WithInstance(ctx, instance), req)
 		}
 	}
-
 	host, err := hostFromContext(interceptorCtx, headerName)
 	if err != nil {
 		return nil, status.Error(codes.NotFound, err.Error())
 	}
 	instance, err := verifier.InstanceByHost(interceptorCtx, host)
 	if err != nil {
-		notFoundErr := new(zerrors.NotFoundError)
-		if errors.As(err, &notFoundErr) {
-			notFoundErr.Message = translator.LocalizeFromCtx(ctx, notFoundErr.GetMessage(), nil)
+		err = fmt.Errorf("unable to set instance using origin %s (ExternalDomain is %s): %w", zitadel_http.ComposedOrigin(ctx), externalDomain, err)
+		zErr := new(zerrors.ZitadelError)
+		if errors.As(err, &zErr) {
+			zErr.SetMessage(translator.LocalizeFromCtx(ctx, zErr.GetMessage(), nil))
+			zErr.Parent = err
+			err = zErr
 		}
 		return nil, status.Error(codes.NotFound, err.Error())
 	}
diff --git a/internal/api/grpc/server/middleware/instance_interceptor_test.go b/internal/api/grpc/server/middleware/instance_interceptor_test.go
index 5de348c8d..132ced4e6 100644
--- a/internal/api/grpc/server/middleware/instance_interceptor_test.go
+++ b/internal/api/grpc/server/middleware/instance_interceptor_test.go
@@ -137,7 +137,7 @@ func Test_setInstance(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got, err := setInstance(tt.args.ctx, tt.args.req, tt.args.info, tt.args.handler, tt.args.verifier, tt.args.headerName, nil)
+			got, err := setInstance(tt.args.ctx, tt.args.req, tt.args.info, tt.args.handler, tt.args.verifier, tt.args.headerName, "", nil)
 			if (err != nil) != tt.res.err {
 				t.Errorf("setInstance() error = %v, wantErr %v", err, tt.res.err)
 				return
diff --git a/internal/api/grpc/server/server.go b/internal/api/grpc/server/server.go
index c957dda02..4f0a6140b 100644
--- a/internal/api/grpc/server/server.go
+++ b/internal/api/grpc/server/server.go
@@ -39,6 +39,7 @@ func CreateServer(
 	authConfig authz.Config,
 	queries *query.Queries,
 	hostHeaderName string,
+	externalDomain string,
 	tlsConfig *tls.Config,
 	accessSvc *logstore.Service[*record.AccessLog],
 ) *grpc.Server {
@@ -50,7 +51,7 @@ func CreateServer(
 				middleware.DefaultTracingServer(),
 				middleware.MetricsHandler(metricTypes, grpc_api.Probes...),
 				middleware.NoCacheInterceptor(),
-				middleware.InstanceInterceptor(queries, hostHeaderName, system_pb.SystemService_ServiceDesc.ServiceName, healthpb.Health_ServiceDesc.ServiceName),
+				middleware.InstanceInterceptor(queries, hostHeaderName, externalDomain, system_pb.SystemService_ServiceDesc.ServiceName, healthpb.Health_ServiceDesc.ServiceName),
 				middleware.AccessStorageInterceptor(accessSvc),
 				middleware.ErrorHandler(),
 				middleware.LimitsInterceptor(system_pb.SystemService_ServiceDesc.ServiceName),
diff --git a/internal/api/http/middleware/instance_interceptor.go b/internal/api/http/middleware/instance_interceptor.go
index ac944278b..4b315d5a7 100644
--- a/internal/api/http/middleware/instance_interceptor.go
+++ b/internal/api/http/middleware/instance_interceptor.go
@@ -19,16 +19,17 @@ import (
 )
 
 type instanceInterceptor struct {
-	verifier        authz.InstanceVerifier
-	headerName      string
-	ignoredPrefixes []string
-	translator      *i18n.Translator
+	verifier                   authz.InstanceVerifier
+	headerName, externalDomain string
+	ignoredPrefixes            []string
+	translator                 *i18n.Translator
 }
 
-func InstanceInterceptor(verifier authz.InstanceVerifier, headerName string, ignoredPrefixes ...string) *instanceInterceptor {
+func InstanceInterceptor(verifier authz.InstanceVerifier, headerName, externalDomain string, ignoredPrefixes ...string) *instanceInterceptor {
 	return &instanceInterceptor{
 		verifier:        verifier,
 		headerName:      headerName,
+		externalDomain:  externalDomain,
 		ignoredPrefixes: ignoredPrefixes,
 		translator:      newZitadelTranslator(),
 	}
@@ -55,9 +56,12 @@ func (a *instanceInterceptor) handleInstance(w http.ResponseWriter, r *http.Requ
 	}
 	ctx, err := setInstance(r, a.verifier, a.headerName)
 	if err != nil {
-		caosErr := new(zerrors.NotFoundError)
-		if errors.As(err, &caosErr) {
-			caosErr.Message = a.translator.LocalizeFromRequest(r, caosErr.GetMessage(), nil)
+		err = fmt.Errorf("unable to set instance using origin %s (ExternalDomain is %s): %w", zitadel_http.ComposedOrigin(r.Context()), a.externalDomain, err)
+		zErr := new(zerrors.ZitadelError)
+		if errors.As(err, &zErr) {
+			zErr.SetMessage(a.translator.LocalizeFromRequest(r, zErr.GetMessage(), nil))
+			zErr.Parent = err
+			err = zErr
 		}
 		http.Error(w, err.Error(), http.StatusNotFound)
 		return
@@ -68,13 +72,13 @@ func (a *instanceInterceptor) handleInstance(w http.ResponseWriter, r *http.Requ
 
 func setInstance(r *http.Request, verifier authz.InstanceVerifier, headerName string) (_ context.Context, err error) {
 	ctx := r.Context()
-
 	authCtx, span := tracing.NewServerInterceptorSpan(ctx)
 	defer func() { span.EndWithError(err) }()
 
 	host, err := HostFromRequest(r, headerName)
+
 	if err != nil {
-		return nil, zerrors.ThrowNotFound(err, "INST-zWq7X", "Errors.Instance.NotFound")
+		return nil, zerrors.ThrowNotFound(err, "INST-zWq7X", "Errors.IAM.NotFound")
 	}
 
 	instance, err := verifier.InstanceByHost(authCtx, host)
diff --git a/internal/query/instance.go b/internal/query/instance.go
index e528f3bcb..8bc83b2d4 100644
--- a/internal/query/instance.go
+++ b/internal/query/instance.go
@@ -6,6 +6,7 @@ import (
 	_ "embed"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"strings"
 	"time"
 
@@ -196,7 +197,12 @@ var (
 
 func (q *Queries) InstanceByHost(ctx context.Context, host string) (_ authz.Instance, err error) {
 	ctx, span := tracing.NewSpan(ctx)
-	defer func() { span.EndWithError(err) }()
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("unable to get instance by host %s: %w", host, err)
+		}
+		span.EndWithError(err)
+	}()
 
 	domain := strings.Split(host, ":")[0] // remove possible port
 	instance, scan := scanAuthzInstance(host, domain)
diff --git a/internal/static/i18n/bg.yaml b/internal/static/i18n/bg.yaml
index 85975c4f5..566f4c207 100644
--- a/internal/static/i18n/bg.yaml
+++ b/internal/static/i18n/bg.yaml
@@ -330,7 +330,7 @@ Errors:
       NotActive: Грантът по проекта не е активен
       NotInactive: Грантът по проекта не е неактивен
   IAM:
-    NotFound: Екземплярът не е намерен. Вижте https://zitadel.com/docs/self-hosting/manage/custom-domain
+    NotFound: IAM не е намерен. Уверете се, че сте получили правилния домейн. Вижте https://zitadel.com/docs/apis/introduction#domains
     Member:
       RolesNotChanged: Ролите не са сменени
     MemberInvalid: Членът е невалиден
diff --git a/internal/static/i18n/cs.yaml b/internal/static/i18n/cs.yaml
index dfb7f75ab..619371c33 100644
--- a/internal/static/i18n/cs.yaml
+++ b/internal/static/i18n/cs.yaml
@@ -327,7 +327,7 @@ Errors:
       NotActive: Grant projektu není aktivní
       NotInactive: Grant projektu není neaktivní
   IAM:
-    NotFound: Instance nenalezena. Podívejte se na https://zitadel.com/docs/self-hosting/manage/custom-domain
+    NotFound: Instance nebyla nalezena. Ujistěte se, že jste získali správnou doménu. Podívejte se na https://zitadel.com/docs/apis/introduction#domains
     Member:
       RolesNotChanged: Role nebyly změněny
     MemberInvalid: Člen je neplatný
diff --git a/internal/static/i18n/de.yaml b/internal/static/i18n/de.yaml
index 5876a5c67..7e2474091 100644
--- a/internal/static/i18n/de.yaml
+++ b/internal/static/i18n/de.yaml
@@ -328,7 +328,7 @@ Errors:
       NotActive: Projekt Grant ist nicht aktiv
       NotInactive: Projekt Grant ist nicht inaktiv
   IAM:
-    NotFound: Instanz nicht gefunden. Schau dir https://zitadel.com/docs/self-hosting/manage/custom-domain an
+    NotFound: Instanz nicht gefunden. Stelle sicher, dass Du die richtige Domain hast. Schau unter https://zitadel.com/docs/apis/introduction#domains
     Member:
       RolesNotChanged: Rollen wurden nicht verändert
     MemberInvalid: Member ist ungültig
diff --git a/internal/static/i18n/en.yaml b/internal/static/i18n/en.yaml
index 5a20617cb..f7a7ad40c 100644
--- a/internal/static/i18n/en.yaml
+++ b/internal/static/i18n/en.yaml
@@ -328,7 +328,7 @@ Errors:
       NotActive: Project grant is not active
       NotInactive: Project grant is not inactive
   IAM:
-    NotFound: Instance not found. Check out https://zitadel.com/docs/self-hosting/manage/custom-domain
+    NotFound: Instance not found. Make sure you got the domain right. Check out https://zitadel.com/docs/apis/introduction#domains
     Member:
       RolesNotChanged: Roles have not been changed
     MemberInvalid: Member is invalid
diff --git a/internal/static/i18n/es.yaml b/internal/static/i18n/es.yaml
index deddad8a3..87609eed9 100644
--- a/internal/static/i18n/es.yaml
+++ b/internal/static/i18n/es.yaml
@@ -328,7 +328,7 @@ Errors:
       NotActive: La concesión del proyecto no está activa
       NotInactive: La concesión del proyecto no está inactiva
   IAM:
-    NotFound: Instancia no encontrada. Consulta https://zitadel.com/docs/self-hosting/manage/custom-domain
+    NotFound: Instancia no encontrada. Asegúrate de que tienes el dominio correcto. Consulta https://zitadel.com/docs/apis/introduction#domains
     Member:
       RolesNotChanged: Los roles no han cambiado
     MemberInvalid: El miembro no es válido
diff --git a/internal/static/i18n/fr.yaml b/internal/static/i18n/fr.yaml
index 688994eae..66f48348f 100644
--- a/internal/static/i18n/fr.yaml
+++ b/internal/static/i18n/fr.yaml
@@ -328,7 +328,7 @@ Errors:
       NotActive: La subvention de projet n'est pas active
       NotInactive: La subvention du projet n'est pas inactive
   IAM:
-    NotFound: Instance non trouvée. Consultez https://zitadel.com/docs/self-hosting/manage/custom-domain
+    NotFound: IAM non trouvé. Assurez-vous que vous avez la bonne organisation. Vérifiez https://zitadel.com/docs/apis/introduction#organizations
     Member:
       RolesNotChanged: Les rôles n'ont pas été modifiés
     MemberInvalid: Le membre n'est pas valide
diff --git a/internal/static/i18n/it.yaml b/internal/static/i18n/it.yaml
index 81ff5e51e..279bab293 100644
--- a/internal/static/i18n/it.yaml
+++ b/internal/static/i18n/it.yaml
@@ -329,7 +329,7 @@ Errors:
       NotActive: Grant del progetto non è attivo
       NotInactive: Grant del progetto non è inattivo
   IAM:
-    NotFound: Istanza non trovata. Controlla https://zitadel.com/docs/self-hosting/manage/custom-domain
+    NotFound: IAM non trovato. Assicurati di avere il dominio corretto. Guarda su https://zitadel.com/docs/apis/introduction#domains
     Member:
       RolesNotChanged: I ruoli non sono stati cambiati
     MemberInvalid: Il membro non è valido
diff --git a/internal/static/i18n/ja.yaml b/internal/static/i18n/ja.yaml
index 22ad9a7c6..7a0442e04 100644
--- a/internal/static/i18n/ja.yaml
+++ b/internal/static/i18n/ja.yaml
@@ -317,7 +317,7 @@ Errors:
       NotActive: プロジェクトグラントはアクティブではありません
       NotInactive: プロジェクトグラントは非アクティブではありません
   IAM:
-    NotFound: インスタンスが見つかりません https://zitadel.com/docs/self-hosting/manage/custom-domain
+    NotFound: IAMが見つかりません。正しいドメインを持っていることを確認してください。 https://zitadel.com/docs/apis/introduction#domains を参照してください
     Member:
       RolesNotChanged: ロールは変更されていません
     MemberInvalid: 無効なメンバーです
diff --git a/internal/static/i18n/mk.yaml b/internal/static/i18n/mk.yaml
index 59d40a57e..44ea7a59f 100644
--- a/internal/static/i18n/mk.yaml
+++ b/internal/static/i18n/mk.yaml
@@ -327,7 +327,7 @@ Errors:
       NotActive: Овластувањето за проектот не е активно
       NotInactive: Овластувањето за проектот не е неактивно
   IAM:
-    NotFound: Инстанцата не е пронајдена. Проверете https://zitadel.com/docs/self-hosting/manage/custom-domain
+    NotFound: IAM не е пронајден. Проверете дали имате точен домен. Погледнете на https://zitadel.com/docs/apis/introduction#domains
     Member:
       RolesNotChanged: Улогите не се променети
     MemberInvalid: Членот е невалиден
diff --git a/internal/static/i18n/nl.yaml b/internal/static/i18n/nl.yaml
index eea39453e..8a8fc78dd 100644
--- a/internal/static/i18n/nl.yaml
+++ b/internal/static/i18n/nl.yaml
@@ -328,7 +328,7 @@ Errors:
       NotActive: Projecttoekenning is niet actief
       NotInactive: Projecttoekenning is niet gedeactiveerd
   IAM:
-    NotFound: Instantie niet gevonden. Bekijk https://zitadel.com/docs/self-hosting/manage/custom-domain
+    NotFound: IAM niet gevonden. Zorg ervoor dat u het juiste domein heeft. Kijk op https://zitadel.com/docs/apis/introduction#domains
     Member:
       RolesNotChanged: Rollen zijn niet veranderd
     MemberInvalid: Lid is ongeldig
diff --git a/internal/static/i18n/pl.yaml b/internal/static/i18n/pl.yaml
index ebcd9284b..fc2d7f620 100644
--- a/internal/static/i18n/pl.yaml
+++ b/internal/static/i18n/pl.yaml
@@ -328,7 +328,7 @@ Errors:
       NotActive: Grant projektu jest nieaktywny
       NotInactive: Grant projektu nie jest nieaktywny
   IAM:
-    NotFound: Instancja nie znaleziona. Sprawdź https://zitadel.com/docs/self-hosting/manage/custom-domain
+    NotFound: IAM nie znaleziony. Upewnij się, że masz poprawną domenę. Sprawdź https://zitadel.com/docs/apis/introduction#domains
     Member:
       RolesNotChanged: Role nie zmienione
     MemberInvalid: Członek jest nieprawidłowy
diff --git a/internal/static/i18n/pt.yaml b/internal/static/i18n/pt.yaml
index b5cc0f6dd..3ea7cb1b3 100644
--- a/internal/static/i18n/pt.yaml
+++ b/internal/static/i18n/pt.yaml
@@ -326,7 +326,7 @@ Errors:
       NotActive: A concessão do projeto não está ativa
       NotInactive: A concessão do projeto não está inativa
   IAM:
-    NotFound: Instância não encontrada. Confira https://zitadel.com/docs/self-hosting/manage/custom-domain
+    NotFound: IAM não encontrado. Verifique se você tem o domínio correto. Consulte https://zitadel.com/docs/apis/introduction#domains
     Member:
       RolesNotChanged: As funções não foram alteradas
     MemberInvalid: O membro é inválido
diff --git a/internal/static/i18n/ru.yaml b/internal/static/i18n/ru.yaml
index 60a8f3568..76ce4ecb0 100644
--- a/internal/static/i18n/ru.yaml
+++ b/internal/static/i18n/ru.yaml
@@ -321,7 +321,7 @@ Errors:
       NotActive: Грант проекта не активен
       NotInactive: Грант проекта не неактивен
   IAM:
-    NotFound: Экземпляр не найден. Проверьте https://zitadel.com/docs/self-hosting/manage/custom-domain
+    NotFound: IAM не найден. Убедитесь, что у вас есть правильный домен. Смотрите на https://zitadel.com/docs/apis/introduction#domains
     Member:
       RolesNotChanged: Роли не изменились
     MemberInvalid: Участник недействителен
diff --git a/internal/static/i18n/zh.yaml b/internal/static/i18n/zh.yaml
index 4d30c732c..71cb5ee63 100644
--- a/internal/static/i18n/zh.yaml
+++ b/internal/static/i18n/zh.yaml
@@ -328,7 +328,7 @@ Errors:
       NotActive: 项目授权不是启用状态
       NotInactive: 项目授权不是停用状态
   IAM:
-    NotFound: 实例未找到。查看 https://zitadel.com/docs/self-hosting/manage/custom-domain
+    NotFound: IAM 未找到。确保您有正确的域。查看 https://zitadel.com/docs/apis/introduction#domains
     Member:
       RolesNotChanged: 角色没有改变
     MemberInvalid: 成员无效