diff --git a/packages/features/CalendarEventBuilder.test.ts b/packages/features/CalendarEventBuilder.test.ts
index dcfa364805..11dabc362e 100644
--- a/packages/features/CalendarEventBuilder.test.ts
+++ b/packages/features/CalendarEventBuilder.test.ts
@@ -26,11 +26,14 @@ describe("CalendarEventBuilder", () => {
       })
       .build();
 
-    expect(event.bookerUrl).toBe("https://cal.com/user/test-slug");
-    expect(event.title).toBe("Test Event");
-    expect(event.startTime).toBe(mockStartTime);
-    expect(event.endTime).toBe(mockEndTime);
-    expect(event.additionalNotes).toBe("Some notes");
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.bookerUrl).toBe("https://cal.com/user/test-slug");
+      expect(event.title).toBe("Test Event");
+      expect(event.startTime).toBe(mockStartTime);
+      expect(event.endTime).toBe(mockEndTime);
+      expect(event.additionalNotes).toBe("Some notes");
+    }
   });
 
   it("should create an event with event type details", () => {
@@ -50,11 +53,14 @@ describe("CalendarEventBuilder", () => {
       })
       .build();
 
-    expect(event.type).toBe("test-slug");
-    expect(event.description).toBe("Test description");
-    expect(event.eventTypeId).toBe(123);
-    expect(event.hideCalendarNotes).toBe(true);
-    expect(event.hideCalendarEventDetails).toBe(false);
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.type).toBe("test-slug");
+      expect(event.description).toBe("Test description");
+      expect(event.eventTypeId).toBe(123);
+      expect(event.hideCalendarNotes).toBe(true);
+      expect(event.hideCalendarEventDetails).toBe(false);
+    }
   });
 
   it("should create an event with organizer details", () => {
@@ -82,17 +88,20 @@ describe("CalendarEventBuilder", () => {
       })
       .build();
 
-    expect(event.organizer).toEqual({
-      id: 456,
-      name: "John Doe",
-      email: "john@example.com",
-      username: "johndoe",
-      timeZone: "America/New_York",
-      language: {
-        translate: mockTranslate,
-        locale: "en",
-      },
-    });
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.organizer).toEqual({
+        id: 456,
+        name: "John Doe",
+        email: "john@example.com",
+        username: "johndoe",
+        timeZone: "America/New_York",
+        language: {
+          translate: mockTranslate,
+          locale: "en",
+        },
+      });
+    }
   });
 
   it("should handle nameless organizer", () => {
@@ -119,7 +128,10 @@ describe("CalendarEventBuilder", () => {
       })
       .build();
 
-    expect(event.organizer.name).toBe("Nameless");
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.organizer.name).toBe("Nameless");
+    }
   });
 
   it("should create an event with attendees", () => {
@@ -158,7 +170,10 @@ describe("CalendarEventBuilder", () => {
       .withAttendees(attendees)
       .build();
 
-    expect(event.attendees).toEqual(attendees);
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.attendees).toEqual(attendees);
+    }
   });
 
   it("should create an event with metadata and responses", () => {
@@ -192,10 +207,13 @@ describe("CalendarEventBuilder", () => {
       })
       .build();
 
-    expect(event.additionalNotes).toBe("Some notes");
-    expect(event.customInputs).toEqual(customInputs);
-    expect(event.responses).toEqual(responses);
-    expect(event.userFieldsResponses).toEqual(userFieldsResponses);
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.additionalNotes).toBe("Some notes");
+      expect(event.customInputs).toEqual(customInputs);
+      expect(event.responses).toEqual(responses);
+      expect(event.userFieldsResponses).toEqual(userFieldsResponses);
+    }
   });
 
   it("should create an event with location", () => {
@@ -216,8 +234,11 @@ describe("CalendarEventBuilder", () => {
       })
       .build();
 
-    expect(event.location).toBe("Conference Room A");
-    expect(event.conferenceCredentialId).toBe(789);
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.location).toBe("Conference Room A");
+      expect(event.conferenceCredentialId).toBe(789);
+    }
   });
 
   it("should create an event with destination calendar", () => {
@@ -229,6 +250,8 @@ describe("CalendarEventBuilder", () => {
       userId: null,
       eventTypeId: null,
       credentialId: null,
+      createdAt: null,
+      updatedAt: null,
       delegationCredentialId: null,
       domainWideDelegationCredentialId: null,
     };
@@ -247,7 +270,10 @@ describe("CalendarEventBuilder", () => {
       .withDestinationCalendar([destinationCalendar])
       .build();
 
-    expect(event.destinationCalendar).toEqual([destinationCalendar]);
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.destinationCalendar).toEqual([destinationCalendar]);
+    }
   });
 
   it("should create an event with identifiers", () => {
@@ -268,8 +294,11 @@ describe("CalendarEventBuilder", () => {
       })
       .build();
 
-    expect(event.iCalUID).toBe("ical-123");
-    expect(event.iCalSequence).toBe(2);
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.iCalUID).toBe("ical-123");
+      expect(event.iCalSequence).toBe(2);
+    }
   });
 
   it("should create an event with confirmation settings", () => {
@@ -290,8 +319,11 @@ describe("CalendarEventBuilder", () => {
       })
       .build();
 
-    expect(event.requiresConfirmation).toBe(true);
-    expect(event.oneTimePassword).toBeUndefined();
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.requiresConfirmation).toBe(true);
+      expect(event.oneTimePassword).toBeUndefined();
+    }
   });
 
   it("should set oneTimePassword to null when isConfirmedByDefault is true", () => {
@@ -312,8 +344,11 @@ describe("CalendarEventBuilder", () => {
       })
       .build();
 
-    expect(event.requiresConfirmation).toBe(true);
-    expect(event.oneTimePassword).toBeNull();
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.requiresConfirmation).toBe(true);
+      expect(event.oneTimePassword).toBeNull();
+    }
   });
 
   it("should create an event with platform variables", () => {
@@ -336,10 +371,13 @@ describe("CalendarEventBuilder", () => {
       })
       .build();
 
-    expect(event.platformClientId).toBe("client-123");
-    expect(event.platformRescheduleUrl).toBe("https://platform.com/reschedule");
-    expect(event.platformCancelUrl).toBe("https://platform.com/cancel");
-    expect(event.platformBookingUrl).toBe("https://platform.com/booking");
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.platformClientId).toBe("client-123");
+      expect(event.platformRescheduleUrl).toBe("https://platform.com/reschedule");
+      expect(event.platformCancelUrl).toBe("https://platform.com/cancel");
+      expect(event.platformBookingUrl).toBe("https://platform.com/booking");
+    }
   });
 
   it("should create an event with apps status", () => {
@@ -376,7 +414,10 @@ describe("CalendarEventBuilder", () => {
       .withAppsStatus(appsStatus)
       .build();
 
-    expect(event.appsStatus).toEqual(appsStatus);
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.appsStatus).toEqual(appsStatus);
+    }
   });
 
   it("should create an event with video call data", () => {
@@ -401,7 +442,10 @@ describe("CalendarEventBuilder", () => {
       .withVideoCallData(videoCallData)
       .build();
 
-    expect(event.videoCallData).toEqual(videoCallData);
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.videoCallData).toEqual(videoCallData);
+    }
   });
 
   it("should create an event with team information", () => {
@@ -435,7 +479,10 @@ describe("CalendarEventBuilder", () => {
       .withTeam(team)
       .build();
 
-    expect(event.team).toEqual(team);
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.team).toEqual(team);
+    }
   });
 
   it("should create an event with recurring event information", () => {
@@ -459,7 +506,10 @@ describe("CalendarEventBuilder", () => {
       .withRecurring(recurringEvent)
       .build();
 
-    expect(event.recurringEvent).toEqual(recurringEvent);
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.recurringEvent).toEqual(recurringEvent);
+    }
   });
 
   it("should create an event with attendee seat ID", () => {
@@ -477,7 +527,10 @@ describe("CalendarEventBuilder", () => {
       .withAttendeeSeatId("seat-123")
       .build();
 
-    expect(event.attendeeSeatId).toBe("seat-123");
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.attendeeSeatId).toBe("seat-123");
+    }
   });
 
   it("should create an event with UID", () => {
@@ -495,7 +548,10 @@ describe("CalendarEventBuilder", () => {
       .withUid("booking-uid-123")
       .build();
 
-    expect(event.uid).toBe("booking-uid-123");
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.uid).toBe("booking-uid-123");
+    }
   });
 
   it("should create an event with one-time password", () => {
@@ -513,7 +569,10 @@ describe("CalendarEventBuilder", () => {
       .withOneTimePassword("otp123")
       .build();
 
-    expect(event.oneTimePassword).toBe("otp123");
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.oneTimePassword).toBe("otp123");
+    }
   });
 
   it("should create an event with recurring event ID", () => {
@@ -531,9 +590,12 @@ describe("CalendarEventBuilder", () => {
       .withRecurringEventId("recurring-123")
       .build();
 
-    expect(event.existingRecurringEvent).toEqual({
-      recurringEventId: "recurring-123",
-    });
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.existingRecurringEvent).toEqual({
+        recurringEventId: "recurring-123",
+      });
+    }
   });
 
   it("should create a complete calendar event with all properties", () => {
@@ -597,6 +659,8 @@ describe("CalendarEventBuilder", () => {
           userId: 1,
           eventTypeId: 123,
           credentialId: 1,
+          createdAt: null,
+          updatedAt: null,
           delegationCredentialId: null,
           domainWideDelegationCredentialId: null,
         },
@@ -644,26 +708,29 @@ describe("CalendarEventBuilder", () => {
       .build();
 
     // Test that all properties are set correctly
-    expect(event.title).toBe("Complete Test Event");
-    expect(event.type).toBe("complete-test");
-    expect(event.organizer.name).toBe("John Doe");
-    expect(event.attendees).toHaveLength(1);
-    expect(event.location).toBe("Conference Room A");
-    expect(event.iCalUID).toBe("ical-123");
-    expect(event.requiresConfirmation).toBe(true);
-    expect(event.platformClientId).toBe("client-123");
-    expect(event.appsStatus).toHaveLength(1);
-    expect(event.videoCallData?.url).toBe("https://meet.example.com/123");
-    expect(event.team?.name).toBe("Engineering Team");
-    expect(event.recurringEvent?.count).toBe(5);
-    expect(event.attendeeSeatId).toBe("seat-123");
-    expect(event.uid).toBe("booking-uid-123");
-    expect(event.oneTimePassword).toBe("otp123");
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.title).toBe("Complete Test Event");
+      expect(event.type).toBe("complete-test");
+      expect(event.organizer.name).toBe("John Doe");
+      expect(event.attendees).toHaveLength(1);
+      expect(event.location).toBe("Conference Room A");
+      expect(event.iCalUID).toBe("ical-123");
+      expect(event.requiresConfirmation).toBe(true);
+      expect(event.platformClientId).toBe("client-123");
+      expect(event.appsStatus).toHaveLength(1);
+      expect(event.videoCallData?.url).toBe("https://meet.example.com/123");
+      expect(event.team?.name).toBe("Engineering Team");
+      expect(event.recurringEvent?.count).toBe(5);
+      expect(event.attendeeSeatId).toBe("seat-123");
+      expect(event.uid).toBe("booking-uid-123");
+      expect(event.oneTimePassword).toBe("otp123");
+    }
   });
 
-  it("should throw an error when building without required fields", () => {
+  it("should return null when building without required fields", () => {
     const builder = new CalendarEventBuilder();
-    expect(() => builder.build()).toThrow("Missing required fields for calendar event");
+    expect(builder.build()).toBeNull();
   });
 
   it("should create an event from an existing event", () => {
@@ -684,8 +751,11 @@ describe("CalendarEventBuilder", () => {
       })
       .build();
 
-    expect(event.title).toBe("Updated Event");
-    expect(event.type).toBe("existing-type");
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.title).toBe("Updated Event");
+      expect(event.type).toBe("existing-type");
+    }
   });
 
   it("should propagate disableCancelling and disableRescheduling", () => {
@@ -706,7 +776,10 @@ describe("CalendarEventBuilder", () => {
       })
       .build();
 
-    expect(event.disableCancelling).toBe(true);
-    expect(event.disableRescheduling).toBe(true);
+    expect(event).not.toBeNull();
+    if (event) {
+      expect(event.disableCancelling).toBe(true);
+      expect(event.disableRescheduling).toBe(true);
+    }
   });
 });
diff --git a/packages/features/CalendarEventBuilder.ts b/packages/features/CalendarEventBuilder.ts
index eb3abd2914..570829ec99 100644
--- a/packages/features/CalendarEventBuilder.ts
+++ b/packages/features/CalendarEventBuilder.ts
@@ -266,7 +266,7 @@ export class CalendarEventBuilder {
     return this;
   }
 
-  build(): CalendarEvent {
+  build(): CalendarEvent | null {
     // Validate required fields
     if (
       !this.event.startTime ||
@@ -275,7 +275,7 @@ export class CalendarEventBuilder {
       !this.event.bookerUrl ||
       !this.event.title
     ) {
-      throw new Error("Missing required fields for calendar event");
+      return null;
     }
 
     return this.event as CalendarEvent;
diff --git a/packages/features/bookings/lib/getCalEventResponses.ts b/packages/features/bookings/lib/getCalEventResponses.ts
index 29e1e508ed..a87b6fb8de 100644
--- a/packages/features/bookings/lib/getCalEventResponses.ts
+++ b/packages/features/bookings/lib/getCalEventResponses.ts
@@ -7,6 +7,7 @@ import { contructEmailFromPhoneNumber } from "@calcom/lib/contructEmailFromPhone
 import { getBookingWithResponses } from "@calcom/lib/getBooking";
 import { eventTypeBookingFields } from "@calcom/prisma/zod-utils";
 import type { CalendarEvent } from "@calcom/types/Calendar";
+import { HttpError } from "@calcom/lib/http-error";
 
 export const getCalEventResponses = ({
   bookingFields,
@@ -42,7 +43,10 @@ export const getCalEventResponses = ({
   // To set placeholder email for the booking
   if (!!!backwardCompatibleResponses.email) {
     if (typeof backwardCompatibleResponses["attendeePhoneNumber"] !== "string")
-      throw new Error("Both Phone and Email are missing");
+      throw new HttpError({
+        statusCode: 400,
+        message: "Both Phone and Email are missing",
+      });
 
     backwardCompatibleResponses.email = contructEmailFromPhoneNumber(
       backwardCompatibleResponses["attendeePhoneNumber"]
diff --git a/packages/features/bookings/lib/handleNewBooking.ts b/packages/features/bookings/lib/handleNewBooking.ts
index 5afe3715a5..040d1a2c33 100644
--- a/packages/features/bookings/lib/handleNewBooking.ts
+++ b/packages/features/bookings/lib/handleNewBooking.ts
@@ -320,17 +320,35 @@ export const buildEventForTeamEventType = async ({
 
   const teamMembers = await Promise.all(teamMemberPromises);
 
-  evt = CalendarEventBuilder.fromEvent(evt)
-    .withDestinationCalendar([...(evt.destinationCalendar ?? []), ...teamDestinationCalendars])
+  const updatedEvt = CalendarEventBuilder.fromEvent(evt)
+    ?.withDestinationCalendar([...(evt.destinationCalendar ?? []), ...teamDestinationCalendars])
     .build();
 
-  return CalendarEventBuilder.fromEvent(evt)
-    .withTeam({
+  if (!updatedEvt) {
+    throw new HttpError({
+      statusCode: 400,
+      message: "Failed to build event with destination calendar due to missing required fields",
+    });
+  }
+
+  evt = updatedEvt;
+
+  const teamEvt = CalendarEventBuilder.fromEvent(evt)
+    ?.withTeam({
       members: teamMembers,
       name: team?.name || "Nameless",
       id: team?.id ?? 0,
     })
     .build();
+
+  if (!teamEvt) {
+    throw new HttpError({
+      statusCode: 400,
+      message: "Failed to build team event due to missing required fields",
+    });
+  }
+
+  return teamEvt;
 };
 
 function buildTroubleshooterData({
@@ -1168,7 +1186,7 @@ async function handler(
 
   const eventName = getEventName(eventNameObject);
 
-  let evt: CalendarEvent = new CalendarEventBuilder()
+  const builtEvt = new CalendarEventBuilder()
     .withBasicDetails({
       bookerUrl,
       title: eventName,
@@ -1226,20 +1244,44 @@ async function handler(
     })
     .build();
 
+  if (!builtEvt) {
+    throw new HttpError({
+      statusCode: 400,
+      message: "Failed to build calendar event due to missing required fields",
+    });
+  }
+
+  let evt: CalendarEvent = builtEvt;
+
   if (input.bookingData.thirdPartyRecurringEventId) {
-    evt = CalendarEventBuilder.fromEvent(evt)
-      .withRecurringEventId(input.bookingData.thirdPartyRecurringEventId)
+    const updatedEvt = CalendarEventBuilder.fromEvent(evt)
+      ?.withRecurringEventId(input.bookingData.thirdPartyRecurringEventId)
       .build();
+
+    if (!updatedEvt) {
+      throw new HttpError({
+        statusCode: 400,
+        message: "Failed to build event with recurring event ID due to missing required fields",
+      });
+    }
+
+    evt = updatedEvt;
   }
 
   if (isTeamEventType) {
-    evt = await buildEventForTeamEventType({
+    const teamEvt = await buildEventForTeamEventType({
       existingEvent: evt,
       schedulingType: eventType.schedulingType,
       users,
       team: eventType.team,
       organizerUser,
     });
+
+    if (!teamEvt) {
+      throw new HttpError({ statusCode: 400, message: "Failed to build team event" });
+    }
+
+    evt = teamEvt;
   }
 
   // data needed for triggering webhooks
@@ -1357,13 +1399,22 @@ async function handler(
       // Rescheduling logic for the original seated event was handled in handleSeats
       // We want to use new booking logic for the new time slot
       originalRescheduledBooking = null;
-      evt = CalendarEventBuilder.fromEvent(evt)
-        .withIdentifiers({
+      const updatedEvt = CalendarEventBuilder.fromEvent(evt)
+        ?.withIdentifiers({
           iCalUID: getICalUID({
             attendeeId: bookingSeat?.attendeeId,
           }),
         })
         .build();
+
+      if (!updatedEvt) {
+        throw new HttpError({
+          statusCode: 400,
+          message: "Failed to build event with new identifiers due to missing required fields",
+        });
+      }
+
+      evt = updatedEvt;
     }
   }
 
@@ -1484,14 +1535,32 @@ async function handler(
         }
       }
 
-      evt = CalendarEventBuilder.fromEvent(evt)
-        .withUid(booking.uid ?? null)
+      const updatedEvtWithUid = CalendarEventBuilder.fromEvent(evt)
+        ?.withUid(booking.uid ?? null)
         .build();
 
-      evt = CalendarEventBuilder.fromEvent(evt)
-        .withOneTimePassword(booking.oneTimePassword ?? null)
+      if (!updatedEvtWithUid) {
+        throw new HttpError({
+          statusCode: 400,
+          message: "Failed to build event with UID due to missing required fields",
+        });
+      }
+
+      evt = updatedEvtWithUid;
+
+      const updatedEvtWithPassword = CalendarEventBuilder.fromEvent(evt)
+        ?.withOneTimePassword(booking.oneTimePassword ?? null)
         .build();
 
+      if (!updatedEvtWithPassword) {
+        throw new HttpError({
+          statusCode: 400,
+          message: "Failed to build event with one-time password due to missing required fields",
+        });
+      }
+
+      evt = updatedEvtWithPassword;
+
       if (booking && booking.id && eventType.seatsPerTimeSlot) {
         const currentAttendee = booking.attendees.find(
           (attendee) =>