Can I give my customer a hotel voucher to show at the hotel when they arrive?

Yes, your customer can be given a hotel voucher to show at check in, and it is one of the standard documents produced once a hotel booking is confirmed through the hotel booking API.

The voucher normally carries your own brand, your logo and your contact details, so the guest sees your agency and not anyone else. It sets out the guest names, the hotel name and address, the check in and check out dates, the room type, how many guests are staying, and whatever is included such as breakfast. It also carries a booking reference. Most hotels want the supplier or hotel confirmation number on the voucher, and that number is passed through from whoever holds the room, so it appears only once the supplier has returned it. With some suppliers that is immediate, and with others it follows a little later, which is worth knowing if you are booking for travel on the same day.

Bear in mind that the voucher can only show what the supplier sends back. If a supplier does not return a hotel telephone number or a direct contact, it will not appear on the document. A few suppliers also insist on their own voucher layout for certain properties, and in that case the voucher has to go out in the form they require. What the guest sees never needs to include your cost or your markup, so you can send the voucher across without exposing your margins.

Make a test booking at a hotel you know well and look at the voucher it produces, so you can see exactly what reaches your customer before you send one out for real.