From December 26, 2021 to January 2, 2022, Shake Shack is offering a thank you to their customers with a new BOGO offer.
When you buy a ShackBurger using the Shake Shack app or website through your customer account, you’ll be able to add a second ShackBurger to your order for free.
To qualify for this deal, you must be signed into your Shake Shack user account and enter the promo code THANKYOU21. Your second ShackBurger will then be repriced as free, for a maximum savings of $6.39.
This Shake Shack offer can be redeemed one per customer with both pickup and delivery orders.