Many small businesses buy Microsoft 365 and start using it straight away with default settings. A little setup work at the start prevents most security and admin problems later. Use this checklist when you set up a new tenant, or to review an existing one.
1. Secure the admin account first
- Create a dedicated admin account and do not use it for daily email.
- Turn on multi-factor authentication (MFA) for it straight away.
- Keep a second admin or a recovery method, so a lost phone does not lock you out.
2. Set up your domain and email
- Add your own domain so addresses look like name@yourbusiness.co.uk.
- Create mailboxes for each person, and shared mailboxes for addresses like info@ or accounts@.
- Add the DNS records Microsoft asks for, including SPF, DKIM and DMARC, to protect against spoofing.
3. Turn on MFA for everyone
Stolen passwords are one of the most common ways small businesses are breached. MFA blocks most of those attempts. Use an authenticator app rather than text messages where you can.
4. Plan your file storage
- Use SharePoint for shared team files and OneDrive for personal work files.
- Create a simple folder structure and permission groups instead of sharing with individuals.
- Check the sharing settings so files are not open to anyone with a link by default.
5. Protect company data on devices
- Enable device encryption such as BitLocker on Windows laptops.
- Use Intune or the built-in device management features on plans that include them.
- Set a screen lock and automatic updates.
6. Back up what Microsoft does not
Microsoft keeps its service running, but you remain responsible for your data. Deleted files and accidental changes have limited recovery windows. Consider a third-party backup for mail and files if the data is important.
7. Set up onboarding and offboarding
Write a short checklist for new starters and leavers: create or disable the account, transfer files, remove access to shared resources and reclaim the licence.
Which plan do you need?
The plan decides which security and management features you get. Compare the current plans on Microsoft’s website and see our Microsoft 365 vs Google Workspace comparison if you are still choosing.
Frequently asked questions
How long does setup take?
For a team of under ten people, a careful setup usually takes a few hours, plus time to move existing email and files.
Can I migrate my old email?
Yes. Microsoft provides migration tools for common email platforms. Test with one mailbox first.
Do you set this up for businesses?
Yes, see our IT setup services.
