Birchbox Coupon: 15% Off Shop Purchases! Posted by Brandy on July 17, 2017. Subscription Box Coupons & Deals / Birchbox Coupons Hello Subscription may earn compensation via links in this post. Read the full disclosure Save for Later Notification Through 8/15 Birchbox is offering 15% off a $35+ shop purchase with coupon code GIMME15! Add a Mystery Sample Pack before you check out!