diff --git a/packages/features/calendars/lib/CalendarManager.test.ts b/packages/features/calendars/lib/CalendarManager.test.ts
index 0c2effdb5b..a9f7b637d7 100644
--- a/packages/features/calendars/lib/CalendarManager.test.ts
+++ b/packages/features/calendars/lib/CalendarManager.test.ts
@@ -1,17 +1,22 @@
 import { prisma } from "@calcom/prisma/__mocks__/prisma";
-
-import { describe, expect, it, vi, beforeEach } from "vitest";
-
+import type { CalendarEvent } from "@calcom/types/Calendar";
+import { beforeEach, describe, expect, it, vi } from "vitest";
 import {
-  getCalendarCredentials,
   deduplicateCredentialsBasedOnSelectedCalendars,
+  deleteEvent,
+  getCalendarCredentials,
   processEvent,
 } from "./CalendarManager";
+import { getCalendar } from "@calcom/app-store/_utils/getCalendar";
 
 vi.mock("@calcom/prisma", () => ({
   prisma,
 }));
 
+vi.mock("@calcom/app-store/_utils/getCalendar", () => ({
+  getCalendar: vi.fn(),
+}));
+
 vi.mock("@calcom/lib/constants", () => ({
   ORGANIZER_EMAIL_EXEMPT_DOMAINS: "",
   IS_PRODUCTION: false,
@@ -560,4 +565,37 @@ describe("CalendarManager tests", () => {
       expect(uniqueCredentials).toEqual(credentials);
     });
   });
+
+  describe("fn: deleteEvent", () => {
+    beforeEach(() => {
+      vi.clearAllMocks();
+    });
+
+    it("should return early when bookingRefUid is empty string", async () => {
+      vi.mocked(getCalendar).mockResolvedValue({ deleteEvent: vi.fn() } as any);
+
+      const credential = {
+        id: 1,
+        type: "google_calendar",
+        key: { access_token: "test_token" },
+        encryptedKey: null,
+        userId: 1,
+        user: { email: "test@example.com" },
+        teamId: null,
+        appId: "google-calendar",
+        invalid: false,
+        delegationCredentialId: null,
+        delegatedTo: null,
+      };
+
+      const result = await deleteEvent({
+        credential,
+        bookingRefUid: "",
+        event: buildCalendarEvent(),
+        externalCalendarId: "calendar-id",
+      });
+
+      expect(result).toEqual({});
+    });
+  });
 });
diff --git a/packages/features/calendars/lib/CalendarManager.ts b/packages/features/calendars/lib/CalendarManager.ts
index c0422945df..f1eb527d83 100644
--- a/packages/features/calendars/lib/CalendarManager.ts
+++ b/packages/features/calendars/lib/CalendarManager.ts
@@ -546,6 +546,16 @@ export const deleteEvent = async ({
   event: CalendarEvent;
   externalCalendarId?: string | null;
 }): Promise<unknown> => {
+  if (!bookingRefUid) {
+    log.error(
+      "deleteEvent failed - bookingRefUid is empty, skipping calendar deletion to prevent malformed API request",
+      safeStringify({
+        credential: getPiiFreeCredential(credential),
+        event: getPiiFreeCalendarEvent(event),
+      })
+    );
+    return Promise.resolve({});
+  }
   const calendar = await getCalendar(credential, "booking");
   log.debug(
     "Deleting calendar event",