POPSUGAR Must Have Box Flash Deal: $10 Off September Box or Free Gift! Posted by Hello Subscription on September 18, 2017. Subscription Box Coupons & Deals / Popsugar Must Have Box Coupons Make the first comment! Hello Subscription may earn compensation via links in this post. Read the full disclosure Save for LaterGo to commentsNotification POPSUGAR Must Have Box is having a flash sale – use coupon code FALL10 to save $10 off the September box! Check out the review of the September POPSUGAR Must Have Box to find out what’s inside! OR: Use coupon code GLAM to get a FREE NCLA MANI-ER Tool Kit with your September box!