MAK — Multiple Activation Key
Category: activation
Last reviewed by the MSLicenseHub Licensing Desk.
A Multiple Activation Key (MAK) is a specific type of volume license key used to activate Microsoft software, such as Windows or Office, by connecting directly to Microsoft’s hosted activation services. Unlike traditional consumer keys, a single MAK is authorized to activate a specific number of devices—known as the activation limit—controlled by a central pool. Each time a device is activated using this key, one activation is deducted from the pool; once the limit is reached, no further installations can be activated until the organization requests an increase from Microsoft.
Technical Mechanism and Deployment
MAKs function through a one-time communication with Microsoft via the internet or telephone. Once a device is activated via MAK, the activation is permanent for that specific hardware installation, meaning the device does not need to reconnect to the corporate network or a license server to remain "genuine." This distinguishes it from Key Management Service (KMS), which requires devices to check in with a local host every 180 days.
Administrators typically deploy MAKs in two ways:
- MAK Independent Activation: Each computer individually connects to Microsoft over the internet to complete activation.
- MAK Proxy Activation: Used for highly secure or isolated environments, the Volume Activation Management Tool (VAMT) collects installation IDs from multiple machines and sends a single bulk request to Microsoft on their behalf.
Common Misunderstandings
A frequent misconception is that a MAK "burns" a legal license every time it is used. In reality, the "activation count" and the "license entitlement" are separate concepts. An organization may legally own 500 licenses but have an activation limit of 750 to account for hardware replacements or re-imaging. Reinstalling Windows on the same machine may consume an additional activation count even if no new license is legally required. Furthermore, MAKs are often confused with Retail or OEM keys; however, MAKs are strictly for Volume Licensing customers and cannot be legally separated from the underlying agreement.
Comparison with Related Terms
| Term | Difference from MAK |
|---|---|
| KMS (Key Management Service) | Uses a local server for activations; requires periodic renewal; best for large, connected networks. |
| ADB (Active Directory Based Activation) | Activates any domain-joined machine automatically without tracking individual counts. |
| OEM (Original Equipment Manufacturer) | Bound to the hardware by the manufacturer; cannot be moved to new hardware and is not managed via Volume Licensing portals. |
Practical Guidance for Procurement
When reviewing a Microsoft Business and Services Agreement (MBSA) or a Select Plus/Open Value agreement, the MAK will not typically appear as a line item on the quote itself. Instead, the quote will list the specific product SKU (e.g., "Windows 11 Pro Upgrade"). Once the purchase is finalized, the MAK is generated within the Microsoft 365 Admin Center or the Volume Licensing Service Center (VLSC).
What this means when buying: Organizations should opt for MAK activation for remote employees who rarely connect to the VPN, or for "air-gapped" systems in secure facilities. If your activation count reaches zero, you do not necessarily need to buy more licenses; you simply need to contact the Microsoft Activation Center to request an increase in the activation limit, provided your underlying license ownership covers the number of installed instances.
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