KMS vs MAK activation — which should I use?
Last reviewed by the MSLicenseHub Licensing Desk.
KMS and MAK are two activation methods that come with Volume Licensing.
KMS (Key Management Service) runs an activation host on your own network. Clients check in every 180 days to renew activation. KMS needs a minimum count (25 for Windows, 5 for Office) before it starts handing out activations — below that you stay in 30-day grace mode. KMS is the right choice for fleets that are always on the corporate network or VPN.
MAK (Multiple Activation Key) activates each device directly against Microsoft. No on-prem server, no minimum count, no renewal — but each activation burns a count from the key. MAK is the right choice for laptops that may leave the network for months, isolated networks, or small deployments below the KMS threshold.
Apply this to your deployment
- Use rights
- Activation method
- Purchase evidence
Activation is a technical check, not proof of ownership. Match the activation method to the purchasing channel and agreement, and retain the invoice and entitlement records.
Decision checklist
| Check | What to record |
|---|---|
| Product and version | Record the full name, edition, version and part number in the quote. |
| Scope of use | Identify the user, device or deployment; count only the metric applicable to this product. |
| Evidence and support | Retain the agreement, invoice and support lifecycle date; perpetual licensing does not mean perpetual support. |
Official Microsoft terms and licensing guidance · Product support lifecycle
Practical checklist
- Use KMS for 25+ Windows or 5+ Office machines that regularly reach your network.
- Use MAK for roaming laptops, isolated networks or small sites.
- Active Directory-based activation is a simpler alternative to a KMS host for domain-joined machines.
- Get both KMS host and MAK keys from the Volume Licensing section of the Microsoft 365 admin center.
Common mistakes to avoid
- Publishing a KMS host to the internet.
- Using public ‘KMS activators’ — they are piracy tools and a security risk.
- Running out of MAK activation counts without tracking them.
Official source: Microsoft documentation. Licensing terms change; confirm against the current Product Terms before buying.
Still unsure?
Talk to a licensing specialist for a written, signed quote tailored to your environment.
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