The IRS is asking airlines to refund taxes to people who bought tickets before last weekend but are just now taking their trips.

Those travelers might be owed a refund because Congress let the taxes expire.

The Internal Revenue Service said on its website Wednesday that airlines can refund the taxes, just as they do when exchanging a refundable ticket that wasn't used.

But the airlines aren't required to issue the refund, and some are directing customers to the IRS.