convert many KMS to one MAK license or offline licensing KMS client permanent

Dear @Martin,

Thank you for posting your question in the Microsoft Q&A forum.

Based on your description, I understand the details of your deployment scenario. You are correct about the activation behavior:

• KMS (Key Management Service): Activates clients for 180 days and requires periodic renewal by contacting a KMS host. This is not suitable if the PCs will be completely offline.
• MAK (Multiple Activation Key): Activates once and remains valid indefinitely, which is ideal for machines that will not reconnect to the network.

Firstly, you cannot convert or merge KMS client keys into a single MAK key. They are different activation channels with separate entitlements. Microsoft does not provide a way to “trade” KMS keys for MAK keys.

Moreover, in this case, Office Home & Business 2024 is a retail SKU. Retail editions do not support KMS or MAK. Each device needs its own retail product key and activation through a Microsoft account during setup. If offline activation is critical, you’ll need to switch to a volume‑licensed edition such as Office LTSC 2024 (Volume activation for Office supports KMS and MAK only).

Secondly, yes, you can set up a KMS host and integrate it with Active Directory-Based Activation (ADBA), but there are a few conditions:

• You need Volume Licensing editions (e.g., Office LTSC 2024). Retail editions like Office Home & Business 2024 do not support KMS or ADBA.
• You must have a valid KMS host key from your Volume Licensing agreement. For more information, please refer to Key Management Services (KMS) activation planning
  • KMS activations are valid for 180 days, a period known as the activation validity interval. KMS clients must renew their activation by connecting to the KMS host at least once every 180 days to stay activated. By default, KMS client computers attempt to renew their activation every seven days. After a client's activation is renewed, the activation validity interval begins again.
  • A single KMS host can support an unlimited number of KMS clients. If you have more than 50 clients, we recommend that you have at least two KMS hosts in case one of your KMS hosts becomes unavailable. Most organizations can operate with as few as two KMS hosts for their entire infrastructure.
• To Create a Key Management Services (KMS) activation host, please follow the Microsoft Official Document here: Create a Key Management Services (KMS) activation host

Then, if your machines are joined to Active Directory, you can configure ADBA, so activation happens automatically when the device joins the domain. This removes the need for periodic internet checks but still requires domain connectivity. For more information: Activate using Active Directory-based activation and Step-by-step configuration: Active Directory-based activation

I hope this information is helpful. Thank you for your patience and your understanding.

Please understand that our initial response does not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.

If you have any questions, please feel free to reach out. I'm looking forward for your reply.

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