diff --git a/packages/features/calendar-subscription/lib/sync/CalendarSyncService.ts b/packages/features/calendar-subscription/lib/sync/CalendarSyncService.ts
index 3d4d0b75a4..7525d954b1 100644
--- a/packages/features/calendar-subscription/lib/sync/CalendarSyncService.ts
+++ b/packages/features/calendar-subscription/lib/sync/CalendarSyncService.ts
@@ -1,14 +1,25 @@
 import type { CreateRegularBookingData } from "@calcom/features/bookings/lib/dto/types";
-import { IdempotencyKeyService } from "@calcom/lib/idempotencyKey/idempotencyKeyService";
 import handleCancelBooking from "@calcom/features/bookings/lib/handleCancelBooking";
 import type { BookingRepository } from "@calcom/features/bookings/repositories/BookingRepository";
 import type { CalendarSubscriptionEventItem } from "@calcom/features/calendar-subscription/lib/CalendarSubscriptionPort.interface";
+import { APP_NAME } from "@calcom/lib/constants";
+import { IdempotencyKeyService } from "@calcom/lib/idempotencyKey/idempotencyKeyService";
 import logger from "@calcom/lib/logger";
 import { safeStringify } from "@calcom/lib/safeStringify";
 import type { SelectedCalendar } from "@calcom/prisma/client";
 import { metrics } from "@sentry/nextjs";
 
 const log = logger.getSubLogger({ prefix: ["CalendarSyncService"] });
+const CAL_MANAGED_ICAL_UID_SUFFIXES: ReadonlySet<string> = new Set(
+  ["cal.com", "cal.diy", APP_NAME].map((suffix) => suffix.toLowerCase())
+);
+
+const isCalManagedICalUID = (iCalUID?: string | null): boolean => {
+  const suffix = iCalUID?.split("@").at(-1)?.toLowerCase();
+  if (!suffix) return false;
+
+  return CAL_MANAGED_ICAL_UID_SUFFIXES.has(suffix);
+};
 
 /**
  * Service to handle synchronization of calendar events.
@@ -42,10 +53,7 @@ export class CalendarSyncService {
       },
     });
 
-    // only process cal.com calendar events
-    const calEvents = calendarSubscriptionEvents.filter((e) =>
-      e.iCalUID?.toLowerCase()?.endsWith("@cal.com")
-    );
+    const calEvents = calendarSubscriptionEvents.filter((e) => isCalManagedICalUID(e.iCalUID));
 
     metrics.distribution("calendar.sync.handleEvents.events_count", calEvents.length, {
       attributes: {
diff --git a/packages/features/calendar-subscription/lib/sync/__tests__/CalendarSyncService.test.ts b/packages/features/calendar-subscription/lib/sync/__tests__/CalendarSyncService.test.ts
index 859912e18c..f260b6b7a2 100644
--- a/packages/features/calendar-subscription/lib/sync/__tests__/CalendarSyncService.test.ts
+++ b/packages/features/calendar-subscription/lib/sync/__tests__/CalendarSyncService.test.ts
@@ -1,9 +1,7 @@
-import { beforeEach, describe, expect, test, vi } from "vitest";
-
 import type { CalendarSubscriptionEventItem } from "@calcom/features/calendar-subscription/lib/CalendarSubscriptionPort.interface";
 import type { BookingRepository } from "@calcom/lib/server/repository/booking";
 import type { SelectedCalendar } from "@calcom/prisma/client";
-
+import { beforeEach, describe, expect, test, vi } from "vitest";
 import { CalendarSyncService } from "../CalendarSyncService";
 
 const { mockHandleCancelBooking, mockCreateBooking } = vi.hoisted(() => ({
@@ -206,6 +204,21 @@ describe("CalendarSyncService", () => {
       });
     });
 
+    test("should handle default Cal.diy iCalUID", async () => {
+      const eventWithCalDiyUID: CalendarSubscriptionEventItem = {
+        ...mockCalComEvent,
+        iCalUID: "test-booking-uid@Cal.diy",
+      };
+
+      mockBookingRepository.findBookingByUidWithEventType = vi.fn().mockResolvedValue(mockBooking);
+
+      await service.handleEvents(mockSelectedCalendar, [eventWithCalDiyUID]);
+
+      expect(mockBookingRepository.findBookingByUidWithEventType).toHaveBeenCalledWith({
+        bookingUid: "test-booking-uid",
+      });
+    });
+
     test("should handle events with null iCalUID", async () => {
       const eventWithNullUID: CalendarSubscriptionEventItem = {
         ...mockCalComEvent,
@@ -279,7 +292,9 @@ describe("CalendarSyncService", () => {
       mockHandleCancelBooking.mockRejectedValue(new Error("Cancellation failed"));
 
       // Should not throw - errors are caught and logged
-      await expect(service.cancelBooking(mockCancelledEvent, mockSelectedCalendar.userId)).resolves.not.toThrow();
+      await expect(
+        service.cancelBooking(mockCancelledEvent, mockSelectedCalendar.userId)
+      ).resolves.not.toThrow();
 
       expect(mockBookingRepository.findBookingByUidWithEventType).toHaveBeenCalled();
       expect(mockHandleCancelBooking).toHaveBeenCalled();
@@ -290,7 +305,9 @@ describe("CalendarSyncService", () => {
         .fn()
         .mockRejectedValue(new Error("DB connection failed"));
 
-      await expect(service.cancelBooking(mockCancelledEvent, mockSelectedCalendar.userId)).resolves.not.toThrow();
+      await expect(
+        service.cancelBooking(mockCancelledEvent, mockSelectedCalendar.userId)
+      ).resolves.not.toThrow();
 
       expect(mockBookingRepository.findBookingByUidWithEventType).toHaveBeenCalled();
       expect(mockHandleCancelBooking).not.toHaveBeenCalled();
@@ -489,7 +506,9 @@ describe("CalendarSyncService", () => {
       mockCreateBooking.mockRejectedValue(new Error("Rescheduling failed"));
 
       // Should not throw - errors are caught and logged
-      await expect(service.rescheduleBooking(eventWithDifferentStart, mockSelectedCalendar.userId)).resolves.not.toThrow();
+      await expect(
+        service.rescheduleBooking(eventWithDifferentStart, mockSelectedCalendar.userId)
+      ).resolves.not.toThrow();
 
       expect(mockBookingRepository.findBookingByUidWithEventType).toHaveBeenCalled();
       expect(mockCreateBooking).toHaveBeenCalled();
@@ -500,7 +519,9 @@ describe("CalendarSyncService", () => {
         .fn()
         .mockRejectedValue(new Error("DB connection failed"));
 
-      await expect(service.rescheduleBooking(mockCalComEvent, mockSelectedCalendar.userId)).resolves.not.toThrow();
+      await expect(
+        service.rescheduleBooking(mockCalComEvent, mockSelectedCalendar.userId)
+      ).resolves.not.toThrow();
 
       expect(mockBookingRepository.findBookingByUidWithEventType).toHaveBeenCalled();
       expect(mockCreateBooking).not.toHaveBeenCalled();