Birchbox Coupon: Annual Subscription Sale – Just $8.25 a Box! Posted by Hello Subscription on December 26, 2018. Subscription Box Coupons & Deals / Birchbox Coupons Hello Subscription may earn compensation via links in this post. Read the full disclosure Save for Later Notification For a limited time use coupon code BESTYEAR99 to save 10% on your Birchbox annual subscription. The cost will be $99 – just $8.25 per box! Prefer monthly? Just use one of these codes!