Moving to Microsoft 365 unlocks professional email, the latest Office apps, Teams and secure cloud storage. But a migration done badly means downtime, lost emails and frustrated staff. Done well, your team barely notices. Here's how to do it well.

Step 1: Plan and audit

Before touching anything, map out what you have:

  • How many users and mailboxes?
  • Where is email hosted today, and how much data needs moving?
  • What files and shared drives need migrating?
  • Which Microsoft 365 plan fits your needs? (See our M365 vs Google Workspace comparison.)

A clear inventory prevents nasty surprises mid-migration.

Step 2: Set up the tenant

Create your Microsoft 365 tenant, verify your domain, and configure the foundations - users, licences, groups and security settings. This is the point to enable multi-factor authentication and the security basics from our security checklist.

Step 3: Migrate email

Email is usually the most sensitive part. The goal is to move every message, contact and calendar entry with zero loss. Depending on your source system, this is done with migration tools that copy data across in the background while everyone keeps working on the old system - so there's no "big bang" outage.

Step 4: Migrate files

Move shared files into OneDrive and SharePoint, preserving your folder structure and permissions. This is a good moment to tidy up - archive what you don't need and rethink how files are organised.

Step 5: Cut over and configure devices

Once data is synced, you switch the domain's mail records to Microsoft 365 and configure everyone's devices and apps. Outlook, Teams and OneDrive get set up so staff log in and find everything where they expect it.

Step 6: Train, back up and support

  • Train staff on anything new, especially Teams.
  • Set up a backup. Microsoft protects its infrastructure, but you are responsible for your data - a third-party backup is essential, as we explain in the 3-2-1 rule.
  • Have support on hand for the first few days to iron out any wrinkles.

How long does it take?

For a typical SME, a well-planned migration runs over a week or two - much of it happening quietly in the background. The visible disruption to staff should be minimal.

The bottom line

A Microsoft 365 migration is straightforward with proper planning and the right tools - and risky without them. If you'd rather hand the whole project to experts who'll handle it seamlessly, explore our IT support service or request a callback.

Frequently asked questions

How long does a Microsoft 365 migration take?

For a small business it can take from a few days to a couple of weeks depending on data volume and complexity. Good planning keeps disruption to a minimum.

Will we lose email access during migration?

A well-run migration keeps email flowing throughout, with the final switchover timed to cause the least disruption, often outside working hours.

Do we need backup if we move to Microsoft 365?

Yes. Microsoft does not fully back up your data against deletion or ransomware, so third-party backup should be set up as part of the migration.