Do I have to give the guest's passport details when I book a hotel through your API?

No, in most cases you do not need passport details to make a hotel booking through our API. The usual requirement is the lead guest name, and often the names of the other adults sharing the room, along with a contact for the booking itself. That is enough for the large majority of rates you will sell day to day.

There are exceptions, and they come from the supplier or the hotel rather than from us. Some rates are sold only to residents of a particular country, or only to people who are not residents, so the supplier asks for guest nationality before it will confirm. Others ask for the lead guest address, date of birth or a phone number, which is more common when the rate is paid at the hotel or has a local tax attached. When one of these is required, the API tells you at the point of booking, so you can collect it from your customer once instead of guessing in advance.

It is also worth remembering that anything you do not collect at booking, the hotel can still ask for at check in. In many countries the front desk is legally obliged to see a passport or national identity card on arrival, no matter how the reservation was made. So even where the API does not request a document, it helps to remind your customer to carry theirs, and to make sure the guest name you enter matches that document exactly, since name mismatches are the most common cause of problems at the desk.

A good next step is to run a test booking on the rates and destinations you sell most often and note which guest fields come back as required, so your booking form asks for the right details first time.