Can I let other travel agents sell through my white label travel portal and see what each of them sells?

Yes, in most cases you can open your portal to other travel agents and see exactly what each of them sells. This is usually called agent or sub agent access, and it means you give another agency a login to the same portal you already use, but with their own view of it. They search and book in the normal way, and every booking they make is recorded against their name, so your reports show you who sold what and when.

How much freedom you give them is up to you. You can normally set a separate markup for each agent, or one markup for a whole group of agents, so a partner who sends you a lot of business can be given better rates than someone who has just joined. You can also limit what they are allowed to do, for example letting them book but not cancel, or hiding certain suppliers from them completely.

Payment is the part worth thinking about early. Some agencies ask their sub agents to pay by card at the time of booking, and others give them a credit balance or a deposit account that goes down with each booking and has to be topped up again. Whether a particular payment method is available to you depends on your payment provider and the plan you are on, so it is worth confirming that before you promise anything to a partner.

Before you invite anyone in, decide what markup each agent should get, what they should and should not be allowed to do, and how they will pay you, then set up one test agent login and make a booking through it yourself so you can see the whole flow from their side.