Can I make a booking for a large group travelling together on my portal?

Yes, you can handle groups, but a large party is treated differently from an ordinary booking and you should expect part of it to be arranged by hand.

For flights, most airline systems treat a party above a certain size as a group, and they will not sell that many seats in one ordinary transaction. Your portal will let your staff book up to whatever the supplier allows in a single go, and beyond that you would either split the passengers across more than one booking or ask the airline or your consolidator for a proper group fare. Splitting is quick, but it does not guarantee everyone is seated together, and the two bookings can come out at different prices because seats sell in batches that run out.

Hotels are usually more forgiving. Many suppliers allow several rooms on one booking, and the portal can keep them under a single reference so your staff see the whole group as one job rather than a pile of separate files. Even so, some hotels set their own ceiling on rooms per booking, and a few want to confirm a large party by hand before they accept it. Whether you run into that limit depends on the supplier and on the rate your customer picked.

If group work is a regular part of your business, it is worth telling us early so the portal is set up with it in mind. In the meantime, ask each of your suppliers what their limit is per booking, and check which of your flight sources can quote group fares, before you promise a client one price for the whole party.