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Employment disputes · Microsoft 365

Your leaver's inbox deletes itself in 30 days. A claim can now arrive months later.

From 1 October 2026, the time limit for most employment tribunal claims doubles to six months, and Acas Early Conciliation can already run for up to 12 weeks. Microsoft 365's default leaver settings were never built for that gap. Here is what happens to the data, and how to keep it.

30 daysuntil a leaver's mailbox is gone for good, with no hold
6 monthsnew tribunal time limit for acts from 1 Oct 2026
12 weeksmaximum Acas Early Conciliation, which pauses the clock
1 Oct 2026the date the longer time limit starts to apply

The gap

The evidence disappears long before the claim arrives

This is what Microsoft 365 does by default when you remove a leaver's licence or delete their account, and no hold is in place.

Days after leaving 0306090120150180210240270300 Email Deleted for good Teams chats Leaver's copies go with the mailbox OneDrive account deleted recycle bin, not searchable Gone OneDrive licence removed only read-only archived, billable storage 6-month time limit Latest claim, with 12 weeks of Acas conciliation
Day 0 is when the licence is removed or the account deleted, usually around the dismissal date. A deleted OneDrive sits in a recycle bin until day 123, but eDiscovery can't search it, so it is out of reach after day 30.

The balance

Your retention settings have two jobs

Everyday

Don't keep everything forever

UK GDPR expects personal data to be kept only as long as it's needed, so keeping every email indefinitely isn't the answer.

Your HR adviser or solicitor decides what to keep. IT makes sure it can be kept.
When a dispute starts

Don't let defaults decide

Automatic cleanup doesn't know a dispute has started. Unless someone switches it off, it keeps deleting on schedule.

Where it hides

Teams scatters a leaver's data across three places

Two of them belong to the leaver, so they disappear with the account. Only channel conversations stay with the team.

The leaver uses Teams daily chats 1:1 or in a group shares a file or recording posts in a channel Their mailbox Email, plus a hidden copy of every chat Gone at day 30 Their OneDrive Chat file shares and meeting recordings Gone by day 123 The team's site Channel posts and channel files Stays
Colleagues who stay keep their own copy of a chat, but conversations with other leavers or external guests can vanish completely. When the leaver's OneDrive goes, every file link they posted in a chat stops working.

The fix

Hold first, then offboard

The damage is done by the order of the steps, not by any one step. Same leaver, two sequences.

What usually happens

  1. Employee dismissed
  2. Licence removed the same dayto save the cost
  3. Day 30mailbox and chats deleted
  4. Month 4HR asks for their emails
  5. Nothing left to find

Hold before offboard

  1. Block sign-inlicence stays on
  2. Check with HRdoes this data need keeping?
  3. Apply a holdmailbox, OneDrive, Teams chats
  4. Confirm it applied
  5. Hand files to the manager
  6. Remove the licence
  7. Mailbox kept as inactivesearchable, no licence needed
Microsoft 365 planCan it hold a mailbox?What to do
Business BasicNot on its ownAdd Exchange Online Archiving for at-risk leavers
Business StandardNot on its ownAdd Exchange Online Archiving for at-risk leavers
Business PremiumYes, includedBuild the hold into every leaver checklist

No hold available? Keep the leaver licensed until the risk has passed. One licence costs far less than losing the evidence.

When HR asks

IT's first 48 hours when HR asks you to keep someone's data

HOUR 1

Get the list

  1. Confirm with HR whose data needs keeping
  2. Pause any leaver offboarding already in progress
  3. Don't remove licences or delete accounts yet
SAME DAY

Stop the deletion

  1. Place holds on their mailboxes, OneDrive and Teams chats
  2. Exclude them from any auto-delete or cleanup policies
  3. Check the holds have actually applied
WITHIN 48 HOURS

Record and prepare

  1. Log what was held, when and who asked
  2. Test that an eDiscovery search finds their data
  3. Agree a review date with HR for releasing the holds

Also worth checking

Can you find the data, and does it stay put?

Can you search it quickly?

1 monththe usual deadline for a subject access request, per the ICO
  • Microsoft Purview eDiscovery searches email, OneDrive and Teams chats for one person in one pass
  • Data on personal phones or unmanaged apps sits outside it
  • Run a test search now, not on day 29

Is data leaving with people?

BCCto a personal inbox is the classic way it walks out
  • Data loss prevention rules can flag or block sensitive files going to personal email
  • Alerts for bulk downloads help during notice periods
  • Sensitivity labels mark HR and client material
Leaver risk review

Find out what your leaver process deletes before you need it

We'll review your Microsoft 365 retention and offboarding settings, check your licences can hold data, and build a hold-before-offboard step into your leaver process.

Book a leaver risk review →

We're an IT provider, not employment lawyers. This article covers Microsoft 365 data settings and summarises publicly available information on tribunal time limits and Acas Early Conciliation. It isn't legal advice: for what to keep and your obligations in a specific case, speak to your HR adviser or employment solicitor. Microsoft 365 behaviour correct as of 30 September 2026.

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