https://smashburger.com/bogo-burger-big-dog-details Buy One Burger or Big Dog, Get One Free when you add quantity of 2 burger or Big Dog items to cart and enter promo code SEPBOGO26 at checkout, or mention offer at checkout to redeem in-restaurant. Valid through 10/3/26 at participating US Smashburger retail locations. Select free in-restaurant pickup to save on fees.