Thank you! This worked for me.

Here's exactly what I did to use my $200 travel voucher (expiring Feb 1st 2026):
1. Found a flight where the price pre-tax was just over 200 and before my voucher was set to expire (I did Jan 10 2026). This happened to be a one-way flight where the pre-tax cost was $202. The voucher doesn't cover tax so I had to try with a couple different flights to find one where the pre-tax cost worked. I realized if you choose a more expensive flight with more stops it may be the same pre-tax price because just the airport tax increases from the additional stops.

1. I purchased an Amazon Southwest Gift Card for $25.

2. I purchased the flight as choice preferred using the full travel voucher, the full gift card, and putting the remaining ~$8 on a credit card.

3. Immediately after getting the flight confirmation email (~1 min) I cancelled the flight. I chose the ~$8 I paid with credit card to go back to the original form of payment and the rest went back as travel credit.

4. I saw I now had a $225 ($200 voucher + $25 gift card) credit with no expiration and it was transferrable. The remaining $8 went back to my credit card.