Discover Card Discover offers worthless $40 rental car certificates in return for $20 of cashback bonus. The certificates cannot be used, so you will lose the $20. Discover has several addresses, one of which is in Wilmington, Delaware

Enterprise's said they had cars.  On Discover's site, I found the code (DISCBB) to tell Enterprise's website that I am using one of the certificates ( https://www.discovercard.com/cardmembersvcs/rewards/app/browsePartner?modeCode=CP092 ), and it says that "No black out dates apply" ( https://www.discovercard.com/cardmembersvcs/rewards/app/showAllPartnersTerms ).  However, if I try to reserve online with the code, it says that there are no cars; if I then start another browser window and do not mention the certificate, it says that there are cars.  So they do have cars, just not for anyone using the $20/$40 thing.  I though of calling on the phone, confirming that a car was available, and then saying, "oh wait, I have this certificate", but the rules for the Enterprise certificate require you to use a special phone number and say that you cannot use it at the regular phone number.  So they know as soon as your dial.  Clever.

 

I next tried Alamo.  Discover's site ( https://www.discovercard.com/cardmembersvcs/rewards/app/showAllPartnersTerms ) admits "Blackout dates may apply", but does not say what those dates are.  Also, it says that you do not receive the code until you redeem the cashback for the certificate ( https://www.discovercard.com/cardmembersvcs/rewards/app/browsePartner?modeCode=CP198 ), so you cannot check first to see if you will be able to use it.  Clever.

 

The only other rental car company for which Discover was selling the certificates was National.  I did not check whether the certificates work there, because, at the airport where I am going, National charges over $40 more (without the certificates) than other companies charge there, so it would cost more there with a certificate than it would cost at another company without one.