Can my customers cancel a booking themselves from my portal, or do they have to contact me first?

Yes, in most cases they can, and you also get to decide whether you want to allow it. A white label portal normally gives every traveller a small account area where they can sign in, open a booking they have made and start a cancellation from there. If you would rather keep that in your own hands, the same portal can be set so the traveller only raises a request and nothing is cancelled until someone at your agency approves it.

What actually happens after they click cancel depends on the supplier rules attached to that booking, not on the portal. A hotel rate with a free cancellation window will usually cancel straight away and return a confirmation. A non refundable rate, a special promotional fare or a ticketed flight often cannot be cancelled online at all, and the portal will say so rather than let the traveller think it has gone through. Airlines in particular tend to require the cancellation to go through their own process, and the refund, if any, follows their fare rules.

Because of that mix, the safest setup for most agencies is to allow self service cancellation only where the supplier genuinely supports it, and to route everything else to your team as a request. That way your customer is never told a booking is cancelled when it is not, and you are not left arguing about a refund that was never actually processed.

Before you switch this on, look at the cancellation rules for each product you sell and make one test booking of each type so you can see exactly what your customer will be shown.