Free Sin City Burger at Smashburger With Purchase of Double Burger on 9/12

UPDATE: THEY HAVE CHANGED THIS PROMO AND NOW YOU NEED TO PURCHASE A DOUBLE BURGER TO GET THE SIN CITY BURGER FOR FREE. THEY STILL HAVE THE OLD COUPON UP HERE THAT JUST SAYS FREE BURGER (I DON'T KNOW IF IT WILL WORK). HOWEVER THEY HAVE THE NEW WITH PURCHASE COUPON HERE

Free Sin City Burger at Smashburger With Purchase of Double Burger on 9/12. Click here for a restaurant locator

1. CLICK HERE - these is no barcode on the coupon it's just a picture. You may be able to show on your phone without having to print it out
2. It is also featured on their website here
3. Always Make sure to Please call ahead to make sure your store is participating before going