Your promo code may be expired, but check the error message.
The code you are trying to use is most likely expired or cannot be used towards the booking you are currently trying to make. You should receive an error indicating why it's not redeemable. If you don't or you know the code should be working for you, please let us know immediately via chat or by emailing us at email@example.com. We'll sort out the issue and get you back in business.