Can my customers book more than one room in a single hotel booking on my portal?

Yes, in most cases your customers can book several rooms at once, and the booking comes back as one reservation rather than as separate ones they have to keep track of. On the search page they choose the number of rooms and who is staying in each, and the results then show only the hotels that can actually take that whole party on those dates, with a total price for the rooms together.

There are limits worth knowing. Most suppliers cap how many rooms one booking may hold, and once you go past a handful of rooms the hotel usually treats it as a group booking, which sits outside the normal live rates and has to be arranged directly with the property on its own terms and its own cancellation rules. Child ages matter too, because a room that takes two adults may not take two adults and a child, and the hotel decides that, not the search.

You should also expect the cancellation terms to apply to the booking as a whole. If your customer wants to drop one room out of four, some suppliers allow it and others will only cancel the entire booking and ask you to rebook what is left, which may come back at a different rate if the original one has gone.

The sensible thing is to run a test search for two or three rooms in a city you sell often, take one through to the confirmation page, and read what the cancellation terms say about changing part of the booking before you promise anything to a customer.