Buy One, Get One Free Classic Shake Terms & Conditions: Purchase one classic Shake and receive one classic Shake free in the same transaction. Limited-time-only shakes are excluded. This promotion is valid for one day only on 14 February 2026 at all Shake Shack UK locations, excluding Gatwick. To redeem the offer, guests must enter a valid promotional code at the in-Shack kiosk and add two classic shakes to their basket when placing their order. Or quote the discount at the tills. The complimentary shake will be the lower-priced item. The offer is valid for in-Shack purchases only. One redemption per transaction. The offer is non-transferable, non-exchangeable, and has no cash alternative. It cannot be used in conjunction with any other offer or promotion. Subject to availability. Shake Shack reserves the right to amend or withdraw this promotion at any time, without affecting orders already placed.