Can a hotel booking still fall through after your hotel booking API has given me a confirmation number?

Yes, it can, although it does not happen often. A confirmation from the API means the supplier accepted the booking and issued a reference against it. The room itself still sits in the hotel's own system, so if the property has oversold, withdrawn a room type, or failed to load the allocation correctly, the hotel can release the room days later even though your booking looked confirmed at the time.

How you hear about it depends on the supplier you booked through. Many suppliers push a status change back to us, and the booking in your portal moves from confirmed to cancelled or to on request, so your staff can see it without doing anything. Others only notify the agency by their own message and leave the status unchanged until someone checks. Where the supplier offers a retrieve booking call, we can refresh the live status in your booking list, which is why it is worth re-checking bookings shortly before arrival rather than assuming a confirmation stays good forever.

What happens next is also the supplier's call, not ours. In most cases the money is returned and the supplier offers a comparable property nearby, but whether they absorb any difference in rate is set by their own terms. We can show you the status, the reference and the correspondence, so you have something solid to work with when you speak to them or to your customer.

It is worth asking us which of the suppliers on your plan send automatic status updates, so you know which bookings need a manual look before your customer travels.