Microsoft 365 migration checklist for small businesses

Before you start

1. List every mailbox. Include shared mailboxes (info@, accounts@), aliases, forwarding rules and distribution lists, not just staff.
2. Choose the right licences. Not everyone needs the same plan. Some shared addresses don't need a paid licence at all.
3. Find your domain login. You'll need access to where your domain's DNS is managed. This is the step that most often causes delays.
4. Decide where files will live. Plan a simple SharePoint and Teams structure around how your team works, not a copy of an old messy folder tree.
5. Agree a switch-over date. Quiet periods such as a Friday afternoon or weekend reduce disruption.

Setting up Microsoft 365 properly

1. Verify your domain in Microsoft 365.
2. Turn on multi-factor authentication for every account from day one.
3. Set up email security records: SPF, DKIM and DMARC help stop your domain being spoofed and keep your email out of spam folders.
4. Create shared mailboxes, groups and permissions before anyone logs in.

Moving email

1. Copy existing email across before the switch, so people aren't left with empty inboxes.
2. Change the MX record so new email flows to Microsoft 365, then run a final sync to catch anything that arrived during the change.
3. Set up Outlook and phones for every user, including calendars and contacts.
4. Keep the old service running briefly until you're sure nothing is missing, then cancel it.

Moving files

1. Tidy before you move. Archive or delete what isn't needed.
2. Move into the new structure in SharePoint, with personal files in OneDrive.
3. Set permissions by team or role, not person by person.
4. Show people where things are. Ten minutes of training saves weeks of "where's that file?"

A real example

For Berkia & Whitney, GWB Tec moved 28 mailboxes from Fasthosts to Microsoft 365 and replaced Dropbox with a structured, secure SharePoint setup, including automated creation of new client sites.