If you sell vape products — whether you run a brick-and-mortar shop, an online store, or a convenience store — age verification isn't just a good idea. It's the law. And getting it wrong can cost you thousands in fines, your tobacco license, or even your business. This guide covers everything you need to know about Tobacco 21 compliance, from ID checking best practices to online verification to avoiding the most common mistakes that get retailers stung.