Something I do to consolidate all the small amounts of unused travel funds I have(sometimes 40 here, 70 there, 90 somewhere else) is instead of leaving them all on three confirmation numbers, including different legs of confirmation numbers sometimes ----is book a flight that's $200 for example using all the confirmation numbers and then cancel the flight. This way all the confirmation numbers conslidate into one new number and thats all I have to remember
This can be handy if you're approaching expiration and are planning on requesting reissue as a voucher, in order to make it worth the $100 fee. Otherwise, I wouldn't recommend it unless all the funds have expiration dates very near each other, as doing so will cause all the funds under the new confirmation to take on the earliest expiration date. Proceed with caution.
A different hack - I use up the credit before it expires on new flights
Just kidding - I think the hack as proposed would help if you were facing expiration and planned on requesting a voucher, you certainly wouldn't want to request multipe vouchers and lose $100 on each one when it could be combined.
Home airport MDW, frequent visitor to MCO to see the mouse.
I've consolidated as @bgubs14 suggested after booking several/many flights at the same time then rebooking them all later on after a price drop. I'm sometimes left with 10 or so travel funds for $5-$10. As the flights were all originally purchased on the or near the same date, any change to the expiration date is minimal and it's much easier to use the single consolidated travel fund than 10 $5 funds.
I agree, it's a good "hack", just be careful of the expiration date change as was mentioned earlier.
Now if only I could consolidate drink coupons and get a bigger prize, that would be a great hack.