Can I trust that a hotel room showing in my search results is definitely still available to book?

Not always, and it helps to understand why so you can set the right expectation with your customers. Hotel search is built for speed, so most suppliers answer a search from a regularly refreshed store of rates rather than calling every hotel fresh for every enquiry. In the time between that refresh and the moment you go to book, the last room can be sold by someone else, the hotel can close out that rate, or the supplier can pull the offer. The room really was there when the search ran, the situation simply changed.

This is why a sensible booking flow checks a second time before anyone pays. Before the booking is confirmed, the chosen room and rate are put back to the supplier to be revalidated, and if the room has gone or the price has moved you are told at that point rather than after the customer's card has been charged. How current the first set of results is varies by supplier, as some return live availability and others work from cached rates, so the behaviour you see will differ between the connections on your account.

When a room does drop out, the practical answer is to show the customer a clear message and put the nearest alternatives in front of them straight away, whether that is another room type in the same hotel or a similar property on the same dates. Most of the time something suitable is still there, and the booking is saved if the customer is not left staring at an error.

Worth checking with us which of your hotel suppliers give live availability and confirming that your site handles a failed room gracefully with alternatives rather than a dead end.