diff --git a/apps/edr-passenger-api/src/modules/bookings/guest-booking.service.ts b/apps/edr-passenger-api/src/modules/bookings/guest-booking.service.ts
index f4139d842..1025a42b3 100644
--- a/apps/edr-passenger-api/src/modules/bookings/guest-booking.service.ts
+++ b/apps/edr-passenger-api/src/modules/bookings/guest-booking.service.ts
@@ -260,7 +260,7 @@ export class GuestBookingService {
     await this.createTravelerProfiles(guestPassengerId, passengersData);
 
     // Confirm seats
-    await this.seatsService.confirmSeats(dto.passengers.map(p => p.seatId));
+    await this.seatsService.confirmSeats(dto.passengers.map(p => p.seatId).filter((id): id is string => !!id));
     this.eventEmitter.emit('booking.created', { booking });
 
     return {
@@ -434,7 +434,7 @@ export class GuestBookingService {
     const { guestPassengerId, iamUserId, createdAccount } = await this.resolveGuestPassenger(dto, passengersData[0], req);
 
     // Create booking with outbound seats; return seats confirmed separately
-    const outboundSeatIds = dto.passengers.map(p => p.seatId);
+    const outboundSeatIds = dto.passengers.map(p => p.seatId).filter((id): id is string => !!id);
     const returnSeatIds   = dto.passengers.map(p => p.returnSeatId!);
 
     const booking = await this.prisma.booking.create({
@@ -701,7 +701,7 @@ export class GuestBookingService {
     await this.createTravelerProfiles(guestPassengerId, passengersData);
 
     await Promise.all([
-      this.seatsService.confirmSeats(dto.passengers.map(p => p.seatId)),
+      this.seatsService.confirmSeats(dto.passengers.map(p => p.seatId).filter((id): id is string => !!id)),
       this.seatsService.confirmSeats(dto.passengers.map(p => p.leg2SeatId!)),
     ]);
     this.eventEmitter.emit('booking.created', { booking });
@@ -894,7 +894,7 @@ export class GuestBookingService {
     await this.createTravelerProfiles(guestPassengerId, passengersData);
 
     await Promise.all([
-      this.seatsService.confirmSeats(dto.passengers.map(p => p.seatId)),
+      this.seatsService.confirmSeats(dto.passengers.map(p => p.seatId).filter((id): id is string => !!id)),
       this.seatsService.confirmSeats(dto.passengers.map(p => p.leg2SeatId!)),
       this.seatsService.confirmSeats(dto.passengers.map(p => p.returnSeatId!)),
       this.seatsService.confirmSeats(dto.passengers.map(p => p.returnLeg2SeatId!)),