Yes if you book a flight with a travel fund your reservation will take on the expiration date of the oldest travel fund applied. In some cases it makes more sense to lose a little bit of travel funds to get extra time to use funds should that trip have a possibility of being cancelled. In your case since you bought the tickets at the price you did to begin with it seems you were ok with that price so getting some funds back is just a bonus even if they expire quickly at least you still have a chance to use those funds. Those funds would need to be booked and travel completed by the expiration date. One other thought southwest has been making schedule changes to September and October flights if you get a schedule change you could request a refund and rebook and that way the cash you paid would be refunded and not be a travel fund the voucher would be held as a travel fund under the confirmation number you have. -Blake
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