diff --git a/src/lib/server/email/__tests__/generate-base-url.test.ts b/src/lib/server/email/__tests__/generate-base-url.test.ts
index a34d581..869a452 100644
--- a/src/lib/server/email/__tests__/generate-base-url.test.ts
+++ b/src/lib/server/email/__tests__/generate-base-url.test.ts
@@ -1,6 +1,5 @@
 import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
 import { generateBaseUrl } from "../email-service";
-import type { SelectTenant } from "$lib/server/db/central-schema";
 
 // Mock NODE_ENV
 const mockEnv = vi.hoisted(() => ({
@@ -22,365 +21,16 @@ describe("generateBaseUrl", () => {
     vi.clearAllMocks();
   });
 
-  describe("Development/Local Environment", () => {
-    it("should return localhost URL regardless of tenant", () => {
-      const requestUrl = new URL("http://localhost:5173");
-      const tenant: SelectTenant = {
-        id: "tenant-1",
-        shortName: "acme",
-        longName: "ACME Corp",
-        logo: null,
-        createdAt: new Date(),
-        updatedAt: new Date(),
-        descriptions: { en: "" },
-        languages: ["en"],
-        defaultLanguage: "en",
-        databaseUrl: "",
-        setupState: "SETTINGS",
-        links: { website: "", imprint: "", privacyStatement: "" },
-        domain: "tenant.example.com",
-      };
-
-      const result = generateBaseUrl(requestUrl, tenant);
-      expect(result).toBe("http://localhost:5173");
-    });
-
-    it("should return localhost URL for null tenant", () => {
-      const requestUrl = new URL("http://localhost:3000");
-
-      const result = generateBaseUrl(requestUrl, null);
-      expect(result).toBe("http://localhost:3000");
-    });
-
-    it("should preserve port for localhost", () => {
-      const requestUrl = new URL("http://localhost:8080");
-      const tenant: SelectTenant = {
-        id: "tenant-1",
-        shortName: "test",
-        longName: "Test Corp",
-        descriptions: { en: "" },
-        languages: ["en"],
-        defaultLanguage: "en",
-        databaseUrl: "",
-        setupState: "SETTINGS",
-        logo: null,
-        links: { website: "", imprint: "", privacyStatement: "" },
-        domain: "tenant.example.com",
-        createdAt: new Date(),
-        updatedAt: new Date(),
-      };
-
-      const result = generateBaseUrl(requestUrl, tenant);
-      expect(result).toBe("http://localhost:8080");
-    });
-
-    it("should handle 127.x.x.x addresses", () => {
-      const requestUrl = new URL("http://127.0.0.1:3000");
-      const tenant: SelectTenant = {
-        id: "tenant-1",
-        shortName: "acme",
-        longName: "ACME Corp",
-        descriptions: { en: "" },
-        languages: ["en"],
-        defaultLanguage: "en",
-        databaseUrl: "",
-        setupState: "SETTINGS",
-        logo: null,
-        links: { website: "", imprint: "", privacyStatement: "" },
-        domain: "tenant.example.com",
-        createdAt: new Date(),
-        updatedAt: new Date(),
-      };
-
-      const result = generateBaseUrl(requestUrl, tenant);
-      expect(result).toBe("http://127.0.0.1:3000");
-    });
-
-    it("should handle 192.168.x.x addresses", () => {
-      const requestUrl = new URL("http://192.168.1.100:8080");
-      const tenant: SelectTenant = {
-        id: "tenant-1",
-        shortName: "acme",
-        longName: "ACME Corp",
-        descriptions: { en: "" },
-        languages: ["en"],
-        defaultLanguage: "en",
-        databaseUrl: "",
-        setupState: "SETTINGS",
-        logo: null,
-        links: { website: "", imprint: "", privacyStatement: "" },
-        domain: "tenant.example.com",
-        createdAt: new Date(),
-        updatedAt: new Date(),
-      };
-
-      const result = generateBaseUrl(requestUrl, tenant);
-      expect(result).toBe("http://192.168.1.100:8080");
-    });
+  it("should return localhost with port", () => {
+    const requestUrl = new URL("http://localhost:5173");
+    const result = generateBaseUrl(requestUrl);
+    expect(result).toBe("http://localhost:5173");
   });
 
-  describe("Production Environment", () => {
-    beforeEach(() => {
-      mockEnv.NODE_ENV = "production";
-    });
+  it("should return tenant domain", () => {
+    const requestUrl = new URL("https://example.com");
 
-    it("should return main domain for null tenant", () => {
-      const requestUrl = new URL("https://example.com");
-
-      const result = generateBaseUrl(requestUrl, null);
-      expect(result).toBe("https://example.com");
-    });
-
-    it("should return main domain with port for null tenant", () => {
-      const requestUrl = new URL("https://example.com:8443");
-
-      const result = generateBaseUrl(requestUrl, null);
-      expect(result).toBe("https://example.com:8443");
-    });
-
-    it("should create subdomain URL for tenant on main domain", () => {
-      const requestUrl = new URL("https://example.com");
-      const tenant: SelectTenant = {
-        id: "tenant-1",
-        shortName: "acme",
-        domain: "acme",
-        longName: "ACME Corp",
-        descriptions: { en: "" },
-        languages: ["en"],
-        defaultLanguage: "en",
-        databaseUrl: "",
-        setupState: "SETTINGS",
-        logo: null,
-        links: { website: "", imprint: "", privacyStatement: "" },
-        createdAt: new Date(),
-        updatedAt: new Date(),
-      };
-
-      const result = generateBaseUrl(requestUrl, tenant);
-      expect(result).toBe("https://acme.example.com");
-    });
-
-    it("should create subdomain URL with port", () => {
-      const requestUrl = new URL("https://example.com:8443");
-      const tenant: SelectTenant = {
-        id: "tenant-1",
-        shortName: "acme",
-        longName: "ACME Corp",
-        descriptions: { en: "" },
-        languages: ["en"],
-        defaultLanguage: "en",
-        databaseUrl: "",
-        setupState: "SETTINGS",
-        logo: null,
-        links: { website: "", imprint: "", privacyStatement: "" },
-        domain: "acme",
-        createdAt: new Date(),
-        updatedAt: new Date(),
-      };
-
-      const result = generateBaseUrl(requestUrl, tenant);
-      expect(result).toBe("https://acme.example.com:8443");
-    });
-
-    it("should replace existing subdomain with tenant shortName", () => {
-      const requestUrl = new URL("https://old-tenant.example.com");
-      const tenant: SelectTenant = {
-        id: "tenant-2",
-        shortName: "new-tenant",
-        longName: "New Tenant Corp",
-        descriptions: { en: "" },
-        languages: ["en"],
-        defaultLanguage: "en",
-        databaseUrl: "",
-        setupState: "SETTINGS",
-        logo: null,
-        links: { website: "", imprint: "", privacyStatement: "" },
-        domain: "new-tenant",
-        createdAt: new Date(),
-        updatedAt: new Date(),
-      };
-
-      const result = generateBaseUrl(requestUrl, tenant);
-      expect(result).toBe("https://new-tenant.old-tenant.example.com");
-    });
-
-    it("should replace existing subdomain with port", () => {
-      const requestUrl = new URL("https://old-tenant.example.com:8443");
-      const tenant: SelectTenant = {
-        id: "tenant-2",
-        shortName: "new-tenant",
-        longName: "New Tenant Corp",
-        descriptions: { en: "" },
-        languages: ["en"],
-        defaultLanguage: "en",
-        databaseUrl: "",
-        setupState: "SETTINGS",
-        logo: null,
-        links: { website: "", imprint: "", privacyStatement: "" },
-        domain: "new-tenant",
-        createdAt: new Date(),
-        updatedAt: new Date(),
-      };
-
-      const result = generateBaseUrl(requestUrl, tenant);
-      expect(result).toBe("https://new-tenant.old-tenant.example.com:8443");
-    });
-
-    it("should handle complex subdomains (keep last two parts)", () => {
-      const requestUrl = new URL("https://admin.api.example.com");
-      const tenant: SelectTenant = {
-        id: "tenant-1",
-        shortName: "tenant",
-        longName: "Tenant Corp",
-        descriptions: { en: "" },
-        languages: ["en"],
-        defaultLanguage: "en",
-        databaseUrl: "",
-        setupState: "SETTINGS",
-        logo: null,
-        links: { website: "", imprint: "", privacyStatement: "" },
-        domain: "tenant",
-        createdAt: new Date(),
-        updatedAt: new Date(),
-      };
-
-      const result = generateBaseUrl(requestUrl, tenant);
-      expect(result).toBe("https://tenant.admin.api.example.com");
-    });
-
-    it("should handle http protocol", () => {
-      const requestUrl = new URL("http://example.com");
-      const tenant: SelectTenant = {
-        id: "tenant-1",
-        shortName: "acme",
-        longName: "ACME Corp",
-        descriptions: { en: "" },
-        languages: ["en"],
-        defaultLanguage: "en",
-        databaseUrl: "",
-        setupState: "SETTINGS",
-        logo: null,
-        links: { website: "", imprint: "", privacyStatement: "" },
-        domain: "acme",
-        createdAt: new Date(),
-        updatedAt: new Date(),
-      };
-
-      const result = generateBaseUrl(requestUrl, tenant);
-      expect(result).toBe("http://acme.example.com");
-    });
-
-    it("should return main domain when tenant has no shortName", () => {
-      const requestUrl = new URL("https://example.com");
-      const tenant: SelectTenant = {
-        id: "tenant-1",
-        shortName: "", // Empty shortName
-        longName: "ACME Corp",
-        descriptions: { en: "" },
-        languages: ["en"],
-        defaultLanguage: "en",
-        databaseUrl: "",
-        setupState: "SETTINGS",
-        logo: null,
-        links: { website: "", imprint: "", privacyStatement: "" },
-        domain: "",
-        createdAt: new Date(),
-        updatedAt: new Date(),
-      };
-
-      const result = generateBaseUrl(requestUrl, tenant);
-      expect(result).toBe("https://example.com");
-    });
-  });
-
-  describe("Edge Cases", () => {
-    it("should handle single domain names in production", () => {
-      mockEnv.NODE_ENV = "production";
-      const requestUrl = new URL("https://app");
-      const tenant: SelectTenant = {
-        id: "tenant-1",
-        shortName: "acme",
-        longName: "ACME Corp",
-        descriptions: { en: "" },
-        languages: ["en"],
-        defaultLanguage: "en",
-        databaseUrl: "",
-        setupState: "SETTINGS",
-        logo: null,
-        links: { website: "", imprint: "", privacyStatement: "" },
-        domain: "acme",
-        createdAt: new Date(),
-        updatedAt: new Date(),
-      };
-
-      const result = generateBaseUrl(requestUrl, tenant);
-      expect(result).toBe("https://acme.app");
-    });
-
-    it("should handle localhost in production (still treated as development)", () => {
-      mockEnv.NODE_ENV = "production";
-      const requestUrl = new URL("https://localhost:8443");
-      const tenant: SelectTenant = {
-        id: "tenant-1",
-        shortName: "acme",
-        longName: "ACME Corp",
-        descriptions: { en: "" },
-        languages: ["en"],
-        defaultLanguage: "en",
-        databaseUrl: "",
-        setupState: "SETTINGS",
-        logo: null,
-        links: { website: "", imprint: "", privacyStatement: "" },
-        domain: "tenant.example.com",
-        createdAt: new Date(),
-        updatedAt: new Date(),
-      };
-
-      const result = generateBaseUrl(requestUrl, tenant);
-      expect(result).toBe("https://localhost:8443");
-    });
-
-    it("should handle IP addresses as development", () => {
-      mockEnv.NODE_ENV = "production";
-      const requestUrl = new URL("https://192.168.1.100:8443");
-      const tenant: SelectTenant = {
-        id: "tenant-1",
-        shortName: "acme",
-        longName: "ACME Corp",
-        descriptions: { en: "" },
-        languages: ["en"],
-        defaultLanguage: "en",
-        databaseUrl: "",
-        setupState: "SETTINGS",
-        logo: null,
-        links: { website: "", imprint: "", privacyStatement: "" },
-        domain: "tenant.example.com",
-        createdAt: new Date(),
-        updatedAt: new Date(),
-      };
-
-      const result = generateBaseUrl(requestUrl, tenant);
-      expect(result).toBe("https://192.168.1.100:8443");
-    });
-
-    it("should handle default HTTP port (80)", () => {
-      mockEnv.NODE_ENV = "production";
-      const requestUrl = new URL("http://example.com:80");
-
-      // URL constructor should handle port 80 correctly
-      const result = generateBaseUrl(requestUrl, null);
-      // Default HTTP port shouldn't be included in URL
-      expect(result).toBe("http://example.com");
-    });
-
-    it("should handle default HTTPS port (443)", () => {
-      mockEnv.NODE_ENV = "production";
-      const requestUrl = new URL("https://example.com:443");
-
-      // URL constructor should handle port 443 correctly
-      const result = generateBaseUrl(requestUrl, null);
-      // Default HTTPS port shouldn't be included in URL
-      expect(result).toBe("https://example.com");
-    });
+    const result = generateBaseUrl(requestUrl);
+    expect(result).toBe("https://example.com");
   });
 });
diff --git a/src/lib/server/email/email-service.ts b/src/lib/server/email/email-service.ts
index f654e58..69e6d13 100644
--- a/src/lib/server/email/email-service.ts
+++ b/src/lib/server/email/email-service.ts
@@ -147,7 +147,7 @@ export async function sendPinResetEmail(
       locale,
       user,
       tenant,
-      loginUrl: generateBaseUrl(requestUrl, tenant) ?? "http://localhost:5173",
+      loginUrl: generateBaseUrl(requestUrl),
     },
   });
   const html = renderOutputToHtml(emailRender);
@@ -399,23 +399,10 @@ export async function sendAppointmentUpdatedEmail(
  * @param {SelectTenant | null} tenant - Tenant information (null for global admin)
  * @returns {string} The appropriate base URL
  */
-export function generateBaseUrl(requestUrl: URL, tenant: SelectTenant | null): string {
-  const protocol = requestUrl.protocol;
-  const port = requestUrl.port ? `:${requestUrl.port}` : "";
-  const hostname = requestUrl.hostname;
-
-  // In development, always use the original hostname regardless of tenant
-  if (hostname === "localhost" || hostname.startsWith("127.") || hostname.startsWith("192.168.")) {
-    return `${protocol}//${hostname}${port}`;
-  }
-
-  // In production, handle tenant subdomains.
-  // Exclude the system tenant when determining if we should use the tenant's domain for the URL, as the system tenant does not have a domain and should use the main domain.
-  if (tenant?.domain && tenant.id !== "system") {
-    return `${protocol}//${tenant.domain}.${hostname}${port}`;
-  }
-
-  // For global admin or no tenant, use main domain
+export function generateBaseUrl(url: URL): string {
+  const protocol = url.protocol;
+  const port = url.port ? `:${url.port}` : "";
+  const hostname = url.hostname;
   return `${protocol}//${hostname}${port}`;
 }
 
@@ -437,7 +424,7 @@ export async function sendConfirmationEmail(
   requestUrl: URL,
 ): Promise<void> {
   // Generate appropriate base URL if request URL is provided
-  const baseUrl = requestUrl ? generateBaseUrl(requestUrl, tenant) : "http://localhost:5173";
+  const baseUrl = generateBaseUrl(requestUrl);
   const confirmUrl = `${baseUrl}/confirm/${confirmationCode}`;
   const recipient = user;
   // Generate email