Microsoft 365 is licensed per user, which sounds simple — one licence per email account — until your crew grows or shrinks and the timing doesn't line up. Adding someone is usually the easy part. Removing someone is where businesses get caught out.

How licensing actually works

Each user who needs an email account needs their own licence. Adding one is generally straightforward: extra licences can be bought at any time, made available immediately, and billed for the remaining period rather than a full new cycle.

The part that catches businesses out

Removing a licence isn't always as immediate as adding one. Depending on how a subscription is billed, reducing the number of licences can be limited to a short window — often within about a week of a purchase or renewal — after which any reduction doesn't take effect until the next renewal date (Microsoft Learn: buy or remove licenses). For a trade business where crew size shifts with the season or the job, that can mean paying for a seat that's no longer being used for weeks or months longer than expected.

What to do about it

  • Know your subscription's removal window before you need to use it, not after someone's already gone
  • Unassign the licence from the departing person straight away, even if the seat itself can't be removed from the subscription until later — this stops them accessing the mailbox
  • Time removals around a renewal date where you can see one coming, rather than trying to remove a seat mid-term
  • Keep a running count of who actually has a licence assigned, especially if staff come and go through the year

Common questions

How is Microsoft 365 licensed? Per user, not per business — one licence is needed for each person who needs an email account, rather than one licence covering the whole company.

Can I add a licence any time my crew grows? Yes — extra licences can generally be added at any time and are available immediately, with billing adjusted for the remaining period.

Can I remove a licence as soon as someone leaves? Not always straight away. Depending on how the subscription is billed, reducing licence count can be restricted to a short window after purchase or renewal — otherwise it has to wait until the next renewal.

What should I do if I know someone's about to leave? Check the licence-removal rules for your specific subscription before you're relying on removing it immediately — timing it around a renewal date, where possible, avoids paying for a seat you no longer need.

What's the best way to manage Microsoft 365 users and licences? There are two main options. You can manage it yourself through the Microsoft 365 Admin Center, adding, removing and reassigning licences directly as your crew changes. Or you can use a managed service like SafeSMB, which handles licence assignment and seat changes on your behalf, so staff changes don't become another admin task to stay on top of.

Where to next

Once licensing makes sense, the next thing worth knowing is what you can actually do day to day without needing to call anyone — including managing email from your phone between jobs.