Can I cancel a hotel booking through the API and find out right away how much my customer gets back?

Yes, you can normally cancel a hotel booking through the API, but whether you see the refund figure straight away depends on the supplier that holds the booking. The cancellation itself is a standard function. You send the booking reference, the system passes the request to the supplier, and you get back a status telling you whether the room has been released.

Where it varies is the money. Some suppliers answer a cancellation request immediately and return both the charge they are keeping and the amount being refunded, so your staff can tell the customer there and then. Others accept the request but confirm the outcome later, which means the booking sits in a cancellation requested state until the supplier replies. On a non refundable rate there will usually be nothing to return, and the system will say so rather than offering a refund. Your own directly contracted hotels, if you load any, follow whatever rules you set for them.

It also helps to keep two things apart. The status in your booking system tells you what the supplier has agreed. The actual money reaching your account comes through your settlement with that supplier, and that happens on their schedule. What you choose to give back to your customer, after any fee of your own, stays your decision under your own terms and conditions.

Before you rely on this in front of a customer, try a cancellation on a refundable rate in your test environment, look at exactly what the response tells you, and ask which of the suppliers on your plan cancel instantly rather than on request.