So when you say you booked and cancelled a flight did you apply the voucher to that reservation? If so that voucher is being held as a travel fund under the confirmation number that you cancelled. The travel fund will only be valid for the person who’s name is on it so if you booked for sally joe (as an example ) then only Sally Joe can use that fund. If you didn't apply the voucher to that other reservation it is possible that the LUV voucher has expired. Keep in mind you only have a year from the date of issue to book and complete travel for the voucher to work. You can always reach out to southwest on Twitter and they can help look in to finding out if the voucher was redeemed or expired. -Blake
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