diff --git a/server/cmd/museum/main.go b/server/cmd/museum/main.go
index cc10a67e8b..86f5537c7b 100644
--- a/server/cmd/museum/main.go
+++ b/server/cmd/museum/main.go
@@ -793,6 +793,7 @@ func main() {
 	privateAPI.DELETE("/remote-store/:key", remoteStoreHandler.RemoveKey)
 	privateAPI.GET("/remote-store", remoteStoreHandler.GetKey)
 	privateAPI.GET("/remote-store/feature-flags", remoteStoreHandler.GetFeatureFlags)
+	privateAPI.GET("/custom-domain", remoteStoreHandler.CheckDomain)
 
 	pushHandler := &api.PushHandler{PushController: pushController}
 	privateAPI.POST("/push/token", pushHandler.AddToken)
diff --git a/server/pkg/api/remotestore.go b/server/pkg/api/remotestore.go
index 7752c990f3..e83883c2dc 100644
--- a/server/pkg/api/remotestore.go
+++ b/server/pkg/api/remotestore.go
@@ -73,3 +73,18 @@ func (h *RemoteStoreHandler) GetFeatureFlags(c *gin.Context) {
 	}
 	c.JSON(http.StatusOK, resp)
 }
+
+// CheckDomain returns 200 ok if the custom domain is claimed by any ente user
+func (h *RemoteStoreHandler) CheckDomain(c *gin.Context) {
+	domain := c.Query("domain")
+	if domain == "" {
+		handler.Error(c, stacktrace.Propagate(ente.NewBadRequestWithMessage("domain is missing"), ""))
+		return
+	}
+	_, err := h.Controller.DomainOwner(c, domain)
+	if err != nil {
+		handler.Error(c, stacktrace.Propagate(err, "failed to get feature flags"))
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{})
+}
diff --git a/server/pkg/controller/remotestore/controller.go b/server/pkg/controller/remotestore/controller.go
index e6769ce443..d6932a5aaf 100644
--- a/server/pkg/controller/remotestore/controller.go
+++ b/server/pkg/controller/remotestore/controller.go
@@ -104,6 +104,10 @@ func (c *Controller) GetFeatureFlags(ctx *gin.Context) (*ente.FeatureFlagRespons
 	return response, nil
 }
 
+func (c *Controller) DomainOwner(ctx *gin.Context, domain string) (*int64, error) {
+	return c.Repo.DomainOwner(ctx, domain)
+}
+
 func (c *Controller) _validateRequest(userID int64, key, value string, byAdmin bool) error {
 	if ente.IsValidFlagKey(key) {
 		return stacktrace.Propagate(ente.NewBadRequestWithMessage(fmt.Sprintf("key %s is not allowed", key)), "invalid flag key")
diff --git a/server/pkg/middleware/rate_limit.go b/server/pkg/middleware/rate_limit.go
index bf4c403cfe..26044ba53c 100644
--- a/server/pkg/middleware/rate_limit.go
+++ b/server/pkg/middleware/rate_limit.go
@@ -133,7 +133,8 @@ func (r *RateLimitMiddleware) APIRateLimitForUserMiddleware(urlSanitizer func(_
 // getLimiter, based on reqPath & reqMethod, return instance of limiter.Limiter which needs to
 // be applied for a request. It returns nil if the request is not rate limited
 func (r *RateLimitMiddleware) getLimiter(reqPath string, reqMethod string) *limiter.Limiter {
-	if reqPath == "/users/public-key" {
+	if reqPath == "/users/public-key" ||
+		reqPath == "/custom-domain" {
 		return r.limit200ReqPerMin
 	}
 	if reqPath == "/users/ott" ||
diff --git a/server/pkg/repo/remotestore/repository.go b/server/pkg/repo/remotestore/repository.go
index 681942365c..f2bd8d7789 100644
--- a/server/pkg/repo/remotestore/repository.go
+++ b/server/pkg/repo/remotestore/repository.go
@@ -47,6 +47,24 @@ func (r *Repository) RemoveKey(ctx context.Context, userID int64, key string) er
 	return stacktrace.Propagate(err, "failed to remove key")
 }
 
+func (r *Repository) DomainOwner(ctx context.Context, domain string) (*int64, error) {
+	// Check if the domain is already taken by another user
+	rows := r.DB.QueryRowContext(ctx, `SELECT user_id FROM remote_store
+	   WHERE key_name = $1 AND key_value = $2`,
+		ente.CustomDomain, // $1
+		domain,            // $2
+	)
+	var userID int64
+	err := rows.Scan(&userID)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, stacktrace.Propagate(&ente.ErrNotFoundError, "")
+		}
+		return nil, stacktrace.Propagate(err, "failed to fetch domain owner")
+	}
+	return &userID, nil
+}
+
 // GetValue fetches and return the value for given user_id and key
 func (r *Repository) GetValue(ctx context.Context, userID int64, key string) (string, error) {
 	rows := r.DB.QueryRowContext(ctx, `SELECT key_value FROM remote_store