diff --git a/apps/login/src/app/api/loginname/route.ts b/apps/login/src/app/api/loginname/route.ts
index b6751ae9164..464eddf4e18 100644
--- a/apps/login/src/app/api/loginname/route.ts
+++ b/apps/login/src/app/api/loginname/route.ts
@@ -2,6 +2,7 @@ import { idpTypeToSlug } from "@/lib/idp";
 import {
   getActiveIdentityProviders,
   getLoginSettings,
+  getOrgsByDomain,
   listAuthenticationMethodTypes,
   listUsers,
   startIdentityProviderFlow,
@@ -9,6 +10,8 @@ import {
 import { createSessionForUserIdAndUpdateCookie } from "@/utils/session";
 import { NextRequest, NextResponse } from "next/server";
 
+const ORG_SUFFIX_REGEX = /(?<=@)(.+)/;
+
 export async function POST(request: NextRequest) {
   const body = await request.json();
   if (body) {
@@ -104,14 +107,45 @@ export async function POST(request: NextRequest) {
           loginSettings?.allowRegister &&
           loginSettings?.allowUsernamePassword
         ) {
-          const params: any = { organization };
+          let orgToRegisterOn: string | undefined = organization;
+
+          if (
+            !orgToRegisterOn &&
+            loginName &&
+            ORG_SUFFIX_REGEX.test(loginName)
+          ) {
+            const matched = ORG_SUFFIX_REGEX.exec(loginName);
+            const suffix = matched?.[1] ?? "";
+
+            // this just returns orgs where the suffix is set as primary domain
+            const orgs = await getOrgsByDomain(suffix);
+            const orgToCheckForDiscovery =
+              orgs.result && orgs.result.length === 1
+                ? orgs.result[0].id
+                : undefined;
+
+            const orgLoginSettings = await getLoginSettings(
+              orgToCheckForDiscovery,
+            );
+            if (orgLoginSettings?.allowDomainDiscovery) {
+              orgToRegisterOn = orgToCheckForDiscovery;
+            }
+          }
+
+          const params: any = {};
+
           if (authRequestId) {
             params.authRequestId = authRequestId;
           }
+
           if (loginName) {
             params.email = loginName;
           }
 
+          if (orgToRegisterOn) {
+            params.organization = orgToRegisterOn;
+          }
+
           const registerUrl = new URL(
             "/register?" + new URLSearchParams(params),
             request.url,
diff --git a/apps/login/src/app/login/route.ts b/apps/login/src/app/login/route.ts
index cd56d90e5cd..5b992cbebe6 100644
--- a/apps/login/src/app/login/route.ts
+++ b/apps/login/src/app/login/route.ts
@@ -11,7 +11,7 @@ import {
   createCallback,
   getActiveIdentityProviders,
   getAuthRequest,
-  getOrgByDomain,
+  getOrgsByDomain,
   listSessions,
   startIdentityProviderFlow,
 } from "@/lib/zitadel";
@@ -155,8 +155,10 @@ export async function GET(request: NextRequest) {
           const matched = ORG_DOMAIN_SCOPE_REGEX.exec(orgDomainScope);
           const orgDomain = matched?.[1] ?? "";
           if (orgDomain) {
-            const org = await getOrgByDomain(orgDomain);
-            organization = org?.org?.id ?? "";
+            const orgs = await getOrgsByDomain(orgDomain);
+            if (orgs.result && orgs.result.length === 1) {
+              organization = orgs.result[0].id ?? "";
+            }
           }
         }
       }
diff --git a/apps/login/src/lib/zitadel.ts b/apps/login/src/lib/zitadel.ts
index 73180302e80..bb6603915df 100644
--- a/apps/login/src/lib/zitadel.ts
+++ b/apps/login/src/lib/zitadel.ts
@@ -5,6 +5,7 @@ import {
   createUserServiceClient,
   createIdpServiceClient,
   makeReqCtx,
+  createOrganizationServiceClient,
 } from "@zitadel/client/v2";
 import { createManagementServiceClient } from "@zitadel/client/v1";
 import { createServerTransport } from "@zitadel/node";
@@ -38,10 +39,10 @@ const transport = createServerTransport(
 );
 
 export const sessionService = createSessionServiceClient(transport);
-export const managementService = createManagementServiceClient(transport);
 export const userService = createUserServiceClient(transport);
 export const oidcService = createOIDCServiceClient(transport);
 export const idpService = createIdpServiceClient(transport);
+export const orgService = createOrganizationServiceClient(transport);
 
 export const settingsService = createSettingsServiceClient(transport);
 
@@ -295,8 +296,20 @@ export async function listUsers({
   return userService.listUsers({ queries: queries });
 }
 
-export async function getOrgByDomain(domain: string) {
-  return managementService.getOrgByDomainGlobal({ domain }, {});
+export async function getOrgsByDomain(domain: string) {
+  return orgService.listOrganizations(
+    {
+      queries: [
+        {
+          query: {
+            case: "domainQuery",
+            value: { domain, method: TextQueryMethod.EQUALS },
+          },
+        },
+      ],
+    },
+    {},
+  );
 }
 
 export async function startIdentityProviderFlow({
diff --git a/packages/zitadel-client/src/v3alpha.ts b/packages/zitadel-client/src/v3alpha.ts
index b55626ada23..f403ad37a90 100644
--- a/packages/zitadel-client/src/v3alpha.ts
+++ b/packages/zitadel-client/src/v3alpha.ts
@@ -1,6 +1,6 @@
-import { UserSchemaService } from "@zitadel/proto/zitadel/user/schema/v3alpha/user_schema_service_pb";
-import { UserService } from "@zitadel/proto/zitadel/user/v3alpha/user_service_pb";
+import { ZITADELUsers } from "@zitadel/proto/zitadel/resources/user/v3alpha/user_service_connect";
+import { ZITADELUserSchemas } from "@zitadel/proto/zitadel/resources/userschema/v3alpha/user_schema_service_connect";
 import { createClientFor } from "./helpers";
 
-export const createUserSchemaServiceClient = createClientFor(UserSchemaService);
-export const createUserServiceClient = createClientFor(UserService);
+export const createUserSchemaServiceClient = createClientFor(ZITADELUserSchemas);
+export const createUserServiceClient = createClientFor(ZITADELUsers);