Buy a burger and have your 2nd for free for your study buddy, when you order at the Shack (dine-in or takeaway only) – exclusively for verified Unidays members only. Offer exclusively for verified Unidays members only with a sufficient photo uploaded to their UNiDAYS ID. Discount cannot be used in conjunction with any other vouchers or other in-Shack promotions. One valid student photo ID must be shown to the teams at time of order – quoting UNiDAYS & Study Buddy offer. The 2nd beneficiary of the offer has to be present upon time of order (does not have to be a verified UNIDAYS student) 2nd Burger must be of equal value or less. Offer is only valid Sundays to Wednesdays (the team have a right to reject any students trying to redeem the offer on non-valid days) available for outdoor dining. Valid in UK Shake Shacks only excluding airport and delivery-only locations.