Shake Shack: Buy 1 ShackBurger, Get 1 Free

1. Sign in to your Shake Shack account (free to join).
For mobile orders, download/install the Shake Shack app (iOS, 标Android)
2. Click "Order Now"
3. Select Pickup or Delivery
4. Add quantity of 2 ShackBurgers (Single only) to cart.
5. In cart, apply Buy 1, Get 1 Free promo code THANKU2021 or THANKYOU21
6. Buy 1, Get 1 Free Discount will be applied.
7. Proceed to checkout and complete your order.