Offer valid only on 4/20/26 at participating US Smashburger® retail locations. Offer available for purchases made in-store or online through smashburger.com or Smashburger® app during regular business hours. Store hours may vary. Offer for four (4) classic single burgers for a total of $20 (before taxes). For in-store orders, must mention offer at checkout. To redeem online, must select the “4 Classics Bundle” item under menu category "420 BUNDLE" on smashburger.com or the Smashburger® app. Must enter promo code CLASSIC420 at checkout.  No protein substitutions. No modifications to burgers in the offer. No limit on number of coupons that may be redeemed per transaction or per customer. Not applicable to any applicable sales tax. Cannot be used in conjunction with any other offer, promotion, or discount. Not valid on previous purchases. Not valid on catering orders or orders with third party delivery. No cash value (unless prohibited by law, then cash value is $.005). No substitutions. No rainchecks. Company reserves the right to withdraw or change the offer’s terms and conditions at any time, at Smashburger’s discretion, and without notice. While supplies last. © 2026 Smashburger IP Holder LLC. All rights reserved.