Probation review date calculator
Probation is set by your contract, not by law — but from 1 January 2027 unfair dismissal protection starts at six months. This works out the review deadline on a working day and warns if probation runs past that date.
Rules checked 25 October 2026 against the sources at the foot of this page.
Hold the probation review by Friday, 16 April 2027
- Probation ends
- 1 May 2027
- Unfair dismissal protection starts
- 1 May 2027
- Overlap
- Probation is still running when protection starts, so any decision after that date is made with full unfair dismissal rights in play. Acas notes that ending probation earlier does not remove legal risk.
Probation lengths compared
For someone starting on Mon, 4 Jan 2027 (England and Wales bank holidays, review 14 days before the end). Their unfair dismissal protection starts on Sat, 3 Jul 2027.
| Probation | Ends | Review by | Ends before protection? |
|---|---|---|---|
| 3 months | Sat, 3 Apr 2027 | Fri, 19 Mar 2027 | Yes |
| 12 weeks | Sun, 28 Mar 2027 | Fri, 12 Mar 2027 | Yes |
| 5 months | Thu, 3 Jun 2027 | Thu, 20 May 2027 | Yes |
| 6 months | Sat, 3 Jul 2027 | Fri, 18 Jun 2027 | No — still running |
| 9 months | Sun, 3 Oct 2027 | Fri, 17 Sept 2027 | No — still running |
A review that holds up
- Set objectives in writing in the first week and check in at the halfway point.
- Hold the formal review on or before the deadline, with time to extend if the contract allows it.
- Write down the outcome and the reasons, whatever the outcome.
- For anyone already past six months, follow your disciplinary or capability procedure and the Acas Code.
More in probation periods after the Employment Rights Act. To track every employee at once, use the staff dates tool.
Frequently asked questions
Did the Employment Rights Act create a statutory probation period?
No. An earlier version of the Bill proposed an “initial period of employment”, but the Act as passed in December 2025 simply reduced the unfair dismissal qualifying period to six months. Probation remains a contractual arrangement — Acas says probation can be any length.
How long should probation be after January 2027?
There is no legal length. Many small employers are moving to three to five months so the decision, and any extension, happens before unfair dismissal protection starts at six months. A longer probation is lawful, but decisions after six months are made with full unfair dismissal rights in play.
Can I extend probation past six months?
If the contract allows extension, yes — but extending does not delay unfair dismissal protection, which depends only on length of service. A dismissal after six months needs a fair reason and a fair process.
Why does the review date move?
Wallchart steps the review back to the previous working day when it lands on a weekend or a bank holiday in the part of the UK you choose, using GOV.UK’s bank holiday data.
Sources
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