Can I change the guest name on a hotel booking I have already made through your hotel booking API?

Yes in some cases, but not on every booking. Whether a guest name can be edited after confirmation depends on the supplier behind that rate and on the hotel's own rules. Where the supplier allows it, the change can be sent through the hotel booking API and you get back an updated confirmation. Where the supplier does not allow it, the booking stays in the name it was made in, and the only route is to cancel and book again.

It also helps to know what kind of change you are asking for. Correcting a spelling, a missing middle name or the order of the first and last name is usually the easier case and many suppliers accept it. Replacing the guest with a completely different traveller is often treated as a new booking instead of an amendment, because the room was contracted for the person you named.

Be careful when the rate is non refundable. If the supplier will not amend it and you have to cancel and rebook, you may lose what was already paid for that room, and the price you see on the new search may not be the same as the one you booked at. Some amendments are also not instant, since they go to the hotel as a request, so do not tell your customer it is done until you have the change confirmed back to you in writing.

Before you book, read the amendment and cancellation conditions that come back with the rate, take the guest name exactly as it appears on the passport, and raise any correction as early as you can rather than close to the arrival date.