Microsoft 365 Backup: Do You Need It?

Published 16 June 2026 · Microsoft 365 · by the 365 Techies team — Microsoft Partners & Dell specialists, looking after Dorset since 1995

It is a common and expensive assumption that everything in Microsoft 365 is backed up because it lives in the cloud. Microsoft’s own terms put it plainly: they run the platform and keep it available, and you are responsible for your data. There is a safety net, but it is short and it has gaps.

What Microsoft keeps for you by default

• Email: a deleted message goes to Deleted Items, and once emptied from there it is recoverable for 14 days by default, which an admin can raise to 30. After that it is gone.
• OneDrive and SharePoint files: deleted files sit in the recycle bins for a combined 93 days. OneDrive’s Files Restore can also roll a whole library back to any point in the last 30 days, which is the tool for a ransomware scare.
• A leaver’s account: when a user is deleted, their mailbox and OneDrive are kept for 30 days by default and then removed, unless a retention policy says otherwise.
• Teams: chat messages are stored in mailboxes and follow the mailbox rules; files shared in Teams live in SharePoint and follow the file rules.

Where the gaps are

Three situations fall straight through that net. A former employee’s data discovered missing on day 31. A file encrypted by ransomware on one PC and faithfully synced to every other, then noticed after the 30-day restore window. And anything deleted deliberately by someone with the rights to do it, whether a disgruntled leaver or an attacker who has taken over an account. Retention policies, which most business plans include, plug the deliberate-deletion gap by holding data regardless of what users do, but they are a hold, not a copy: the data stays inside the same tenant, behind the same admin accounts.

What a backup adds

A separate Microsoft 365 backup takes a copy of mail, OneDrive, SharePoint and Teams data on a schedule and stores it outside your tenant, so it survives a deleted user, an emptied recycle bin, a compromised admin or a subscription that lapsed. You can restore a single email from three years ago or a whole mailbox from last Tuesday. Microsoft now sells its own version, Microsoft 365 Backup, priced per gigabyte, alongside the third-party services that have done this for years. Either is fine; the point is that the copy exists and is tested.

So, do you need it?

If your business’s records live in Microsoft 365, the accounts, the customer emails, the contracts, then yes, in the same way you would not run a business without a backup of the office server. A home Microsoft 365 Family subscription is a different case: OneDrive’s 30-day Files Restore and a copy of your photos on an external drive cover most households, and our photo backup guide shows how.

Key points

• Microsoft runs the service; your data is your responsibility
• Emptied email is recoverable for 14 days by default, files for 93
• A deleted user’s mailbox and OneDrive go after 30 days
• Retention holds data in the tenant; a backup keeps a copy outside it
• Businesses whose records live in Microsoft 365 need one; most homes do not