I have TB funds with various expiration dates: I have $100 expiring 05/28/2022 (from the CLEAR promo), and I also have $200 exp. 7/1/26; $200 exp. 11/18/26; and $400 exp. 1/8/27.

In order to hold on to the value of the $100 expiring in a month, I understand I can book a UA metal domestic flight, in Economy, wait 24 hours, then cancel it. (I found a one-way Economy flight for $99, so that would work great.)

But my question is this: will United automatically deduct the TB funds from those that are expiring the soonest, ie., the funds that expire on 5/28/22?