If you fly with any frequency, you’ve probably been asked to give up your seat on an overbooked flight in return for a voucher or credit on future flights. If you do agree to get bumped, it can pay to be careful with your compensation. These days, airlines rarely offer cash and will instead usually offer vouchers for “free” flights.

But a voucher is not cash and has no cash value, and it usually comes with plenty of qualifications and restrictions. One restriction you should definitely avoid is any voucher that requires the purchase of a certain fare class. This means that in order to use it, you’ll end up paying far more than you normally would for a ticket. What you need to ask for is an unrestricted voucher that you can use on any type of fares, any time.