Multiple Activation Key May 2026

Here’s a useful breakdown of — what they are, how they work, when to use them, and potential pitfalls. 1. What Is a Multiple Activation Key (MAK)? A Multiple Activation Key (MAK) is a type of product key used primarily with Microsoft volume licensing programs (e.g., Open, Select, Enterprise Agreements). Unlike a retail key (which activates one or a few devices) or a KMS key (which relies on an on-premises activation server), a MAK is used to activate a specific number of installations directly with Microsoft’s activation servers over the internet or by phone.