Free shake on your birthday

SmashRewards members get a free hand-spun shake in any flavor for their birthday.

Conditions: Free SmashRewards membership with your birthday saved in your account. Valid on your birthday or within 7 days of it. You must be signed in to your account and have another qualifying item in your order. Redeem in-restaurant, online or in the Smashburger app at participating US locations. Not valid on catering or third-party delivery orders, and can't be combined with other offers. One birthday shake per member.