Choose your migration method first
How you move to Microsoft 365 depends on where your email and files live today. The common starting points for UK small and medium businesses are:
- An on-premises Exchange server. Use a cutover migration for smaller organisations, or a staged or hybrid migration if you need to move users in groups.
- A hosted email service or IMAP mailbox. Mailbox contents are copied across with migration tools, then the domain's mail records are switched.
- Google Workspace. Microsoft provides migration tooling for Gmail, calendars, contacts and Google Drive.
- An existing Microsoft 365 tenant, for example after a merger. A tenant-to-tenant migration moves users, mailboxes and files between tenancies.
Shared files on a server or NAS are a separate workstream with its own plan.
Planning a Microsoft 365 move?
We help UK businesses migrate email and files to Microsoft 365 without the disruption.
Pre-migration checklist
- Inventory users and mailboxes, including shared mailboxes, aliases, distribution lists and room calendars.
- Find everything that sends email: scanners, line-of-business software, website contact forms and alerting systems.
- Confirm who controls your domain and DNS. Check the current records with our free DNS lookup tool.
- Map shared folders to their new home: Teams for team collaboration, SharePoint libraries for departmental files, OneDrive for personal work.
- Review permissions so the migration does not copy years of over-generous access.
- Agree a cutover date outside your busiest period, and tell staff what will change.
Picking licences
The Microsoft 365 Business plans most UK SMEs choose between are:
- Business Basic: email, Teams, SharePoint, OneDrive and the web and mobile Office apps.
- Business Standard: everything in Basic plus the desktop Office apps.
- Business Premium: everything in Standard plus Intune device management, Microsoft Defender for Business and Conditional Access.
Plans can be mixed, so staff who only need email and Teams do not have to carry the cost of desktop apps. Businesses working towards Cyber Essentials often find Business Premium the simplest way to meet the device and access controls.
Running the email migration
- Add and verify your domain in Microsoft 365.
- Create user accounts and assign licences.
- Copy mailbox data while the old system is still live.
- Switch the MX record so new mail is delivered to Microsoft 365.
- Run a final sync to pick up anything that arrived during the switch.
- Configure SPF, DKIM and DMARC to protect your domain against spoofing and improve deliverability.
- Reconnect phones and Outlook, which most users can do themselves with a short guide.
Migrate without the headaches
Let our team handle licensing, mailboxes and secure sign-in while you keep working.
Moving files
Use Microsoft's migration tools rather than dragging folders in File Explorer, so dates, versions and permissions are preserved. Copy the bulk of the data ahead of time, then run a short final sync at cutover. Check your upload capacity first with our speed test; on slower connections a large file share can take days to copy.
UK data protection points
- Data location. Microsoft operates UK data centres. Check your tenant's data location in the Microsoft 365 admin centre and record it in your records of processing.
- UK GDPR. Update your records of processing and privacy information to reflect the change. If the migration involves high-risk processing, carry out a data protection impact assessment.
- Cyber Essentials. Cloud services such as Microsoft 365 are in scope for Cyber Essentials, so configure multi-factor authentication and secure settings from day one.
Securing the tenant on day one
- Require multi-factor authentication for every user.
- Block legacy authentication protocols.
- Use separate admin accounts, and keep the number of global admins small.
- Turn on audit logging and alert policies.
- Apply Conditional Access and device compliance policies if you have Business Premium.
Want this set up for you?
Omega IT can configure and manage Microsoft 365 for your team.
After the migration
Train staff on where files now live, how to share externally and how to spot phishing aimed at Microsoft 365 sign-ins. Decommission the old server or email service once you are sure nothing still depends on it. Then add a third-party backup for Microsoft 365: Microsoft keeps the service running, but restoring deleted or encrypted data beyond its retention settings is your responsibility.
How Omega IT can help
We plan and run Microsoft 365 migrations for UK businesses, from licensing advice to post-migration support. See our Microsoft 365 services or request a quote.