# Microsoft 365 migration checklist for small businesses > A practical checklist for moving a small business to Microsoft 365: planning mailboxes and licences, DNS and email security, moving files to SharePoint, and switching over smoothly. Source: https://gwbtec.co.uk/guide-microsoft-365-migration-checklist Guide · Microsoft 365 Moving email and files to Microsoft 365 is one of the best upgrades a small business can make, if it's planned properly. Use this checklist to avoid lost email and confused staff. By [Grant Baxter](https://gwbtec.co.uk/about), founder of GWB Tec, 18+ years in business IT · Published 6 November 2026 ## Before you start - **List every mailbox.** Include shared mailboxes (info@, accounts@), aliases, forwarding rules and distribution lists, not just staff. - **Choose the right licences.** Not everyone needs the same plan. Some shared addresses don't need a paid licence at all. - **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. - **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. - **Agree a switch-over date.** Quiet periods such as a Friday afternoon or weekend reduce disruption. ## Setting up Microsoft 365 properly - **Verify your domain** in Microsoft 365. - **Turn on multi-factor authentication** for every account from day one. - **Set up email security records:** SPF, DKIM and DMARC help stop your domain being spoofed and keep your email out of spam folders. - **Create shared mailboxes, groups and permissions** before anyone logs in. ## Moving email - **Copy existing email across** before the switch, so people aren't left with empty inboxes. - **Change the MX record** so new email flows to Microsoft 365, then run a final sync to catch anything that arrived during the change. - **Set up Outlook and phones** for every user, including calendars and contacts. - **Keep the old service running briefly** until you're sure nothing is missing, then cancel it. ## Moving files - **Tidy before you move.** Archive or delete what isn't needed. - **Move into the new structure** in SharePoint, with personal files in OneDrive. - **Set permissions by team or role,** not person by person. - **Show people where things are.** Ten minutes of training saves weeks of "where's that file?" ## A real example For [Berkia & Whitney](https://gwbtec.co.uk/case-study-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. **Want it done for you?** See [IT consultancy](https://gwbtec.co.uk/it-consultancy) and [SharePoint consultancy](https://gwbtec.co.uk/sharepoint-consultancy). Frequently asked ## Quick answers ### How long does a Microsoft 365 migration take? For a small business, the switch itself is usually quick. Most of the time goes into planning, copying existing email and files, and setting up devices. A well-planned move causes very little disruption. ### Will we lose any email when we move to Microsoft 365? Not if it's done properly. Existing email is copied before the switch, and a final sync after the MX record changes catches anything that arrived in between. ### Do we need to change our email addresses? No. You keep your own domain and addresses; only the service behind them changes. ### Should we move our files to SharePoint or OneDrive? Shared business files belong in SharePoint (often through Teams) so they stay with the business. OneDrive is for each person's own working files. Keep reading ## Related services and guides Case study ### [Berkia & Whitney](https://gwbtec.co.uk/case-study-berkia-whitney) 28 mailboxes moved to Microsoft 365 and SharePoint. Support ### [IT Consultancy](https://gwbtec.co.uk/it-consultancy) Independent advice before you commit. Support ### [SharePoint Consultancy](https://gwbtec.co.uk/sharepoint-consultancy) Document management built around your team. ## Planning a move to Microsoft 365? We'll plan it around how your business works and handle the switch, so your team can keep working. [Talk to GWB Tec](https://gwbtec.co.uk/contact) --- GWB Tec (formerly GWBrix) is a trading name of GWBaxter Ltd, Chippenham, Wiltshire. Company no. 17269247. Phone 01249 471139 · hello@gwbtec.co.uk · Open 9am to 8pm, 7 days a week.