+1-877-777-6475 (US) or +44-161-568-3262 (UK) Contact Booking.com customer service if you cannot locate your confirmation number. Start through the official Help Center or Manage Your Booking options and provide other available booking details. Call +1-877-777-6475 (US) or +44-161-568-3262 (UK) for assistance locating or managing your reservation.