Can my white label travel portal still sell if one of my suppliers stops responding?

Yes, in most cases your white label travel portal keeps selling even when one supplier stops responding, because the portal asks several suppliers at the same time and shows whatever comes back within the time it is allowed to wait. If one of them is slow or offline, the results from the others still appear, and your customer usually sees a shorter list of options rather than an error page.

What you do lose while that supplier is unavailable is its own rates and its own content, so a hotel or a fare that only that supplier sells will simply not be there until it recovers. How often this happens is down to the supplier, not to the portal, and it is one of the reasons agencies who sell heavily into one destination like to have more than one source of supply for it.

There is an important difference between the search stage and the booking stage. If a supplier fails while a customer is completing a booking, that booking cannot be confirmed with them, and the portal will say so plainly and let the customer choose another option rather than show a confirmation for something the supplier has not actually confirmed.

If steady availability matters to your business, it is worth looking at which of your suppliers cover your busiest destinations and making sure at least two of them do, so a quiet spell from one is never a quiet spell for your portal.