If a hotel charges extra taxes or fees that my customer has to pay at the property, will I see those in the API before they book?

Yes, in most cases you will see them before the booking is made, but how much detail you get depends on the supplier behind that property. Hotel rates usually come back from the API split into what the guest pays you now and what the guest pays at the hotel. Taxes that form part of the room rate are normally included in the total you are shown, while charges like a resort fee, a city or tourist tax, or a parking charge are often collected by the property itself at check in and are listed separately from the rate.

Where those extra charges exist, the API usually returns them as part of the rate details, sometimes as an amount and sometimes only as wording written by the supplier. That wording is not always in the same place for every supplier, so it is worth showing it plainly on your booking page instead of tucking it away. A guest who is asked for money at the front desk that nobody warned them about will come back to you, not to the hotel. If a supplier does not send a charge in a proper field, we cannot fill it in for them, and you will only have the text they provide.

The safest way to work is to treat the amount you collect from the customer and the amount the customer will finally spend as two different numbers, and to print both on the confirmation you send out. Check a handful of the properties you sell most often in your test environment and look at what the rate details actually carry for each one, so you know before you go live which suppliers give you a clear amount and which give you only a sentence.