Can a UK probation period be extended?

Yes, where there is a legitimate reason. Common grounds: significant sickness absence preventing fair assessment, mandatory training not completed for reasons beyond the employee's control, performance concerns identified late requiring time to address, or reasonable adjustments needed for disability that affect the original timeline. The extension should be confirmed in writing with clear objectives.

How long is a typical probation extension?

Three months is the most common extension. Some employers use shorter (six to eight weeks) for specific limited concerns; some use longer (six months) for substantial development needs. The extension should be proportionate to the issue being addressed; an extension significantly longer than the underlying concern would justify can be challenged.

What are my rights during an extended probation?

The same rights as during the original probation: shorter contractual notice on both sides, statutory minimum notice once one month of service is complete, statutory holiday accrual, day-one rights (discrimination, whistleblowing, asserting a statutory right). The longer post-probation notice does not apply until the extended probation is confirmed.

Can I refuse a probation extension?

Not strictly; the extension is a unilateral employer decision under the contract. But you can challenge an unfair extension through the employer's grievance procedure. If the extension is being used as a pretext (for example, to delay confirmation while looking for a reason to dismiss), the grievance route is the way to flag this. In practice, accepting the extension and engaging actively is usually the better strategy.

Probation Period Extensions (UK 2026): When, How Long, Rights

When extensions are used

Four common grounds for extending a UK probation:

Significant sickness absence. Where the employee has been absent for a material part of the probation period and there has not been enough opportunity to assess fairly. The extension restores the assessment window.

Outstanding training. Where mandatory training or role-specific qualifications have not been completed for reasons beyond the employee’s control (course availability, scheduling, employer delay). The extension gives time to finish.

Late-identified performance concerns. Where concerns surface late in the original period and the employee has not had a reasonable chance to address them. The extension provides the opportunity to improve.

Reasonable adjustments. Where adjustments for disability or another protected characteristic require longer to take effect. The extension accommodates the adjustments.

Extensions for reasons outside these categories should be challenged. Use the employer’s grievance procedure to flag concerns about an unjustified extension.

How extensions are confirmed

The extension should be confirmed in writing, ideally by email or letter from the line manager and HR. The confirmation document should specify:

The new probation end date.
The reason for the extension.
The specific objectives to be achieved during the extension (usually three to five points).
The support being provided to help achieve those objectives.
The dates of the additional reviews during the extension.
The notice period during the extension (usually the same as the original probation).

Without a written extension document the employee is left guessing what they need to demonstrate. Ask for the extension in writing if it has been communicated only verbally.

Notice during an extended probation

The shorter probation notice continues during the extension. The longer post-probation notice does not start until the extended probation is confirmed.

So a Band 5 NHS employee on a six-month probation extended by three months has one-month notice on both sides for the full nine-month period. The three-month post-probation notice starts only on the date the extended probation is signed off.

For the broader detail on probation notice, see probation period notice period.

What objectives should look like

Strong extension objectives are specific, measurable, achievable, relevant and time-bound. Three to five objectives is the right number; fewer and the bar is too narrow, more and they become impossible to focus on.

Examples of objectives that work:

Complete the outstanding mandatory training modules by the end of week four of the extension.
Demonstrate independent management of three case workloads of the type specified in the job description by the end of week six.
Establish working relationships with the named cross-team stakeholders, with feedback collected at the mid-extension review.
Maintain attendance at the employer-standard level for the duration of the extension.

Examples of objectives that should be pushed back on:

“Improve performance” (too vague).
“Be more proactive” (subjective, hard to measure).
“Demonstrate team fit” (no objective standard).

Your rights during the extension

The same rights apply as during the original probation:

Statutory minimum notice from the employer applies once one month of service is complete (typically already complete by the time of an extension).
Holiday continues to accrue at the statutory and contractual rate.
Statutory sick pay applies subject to the standard eligibility rules.
Day-one rights apply: discrimination, whistleblowing, asserting a statutory right.
Right to request flexible working applies from day one (since April 2024).

Unfair dismissal protection still requires two years of continuous service, which the extension does not help with (the clock runs from the start of employment, not from the start of the extension).

Reviews during the extension

Most employers run additional structured reviews during the extension. The pattern: a mid- extension review halfway through (assessing progress against the objectives), and a final review at the end of the extension to make the confirmation decision.

For the practical detail on what to expect at each review, see probation review meeting.

If you do not pass the extended probation

If the extended probation ends with dismissal, the position is the same as a dismissal during the original probation:

Contractual probation notice applies.
Right of internal appeal applies (if the employer’s policy includes one, which most do).
Day-one tribunal rights apply (discrimination, whistleblowing, statutory rights).
Standard two-year unfair dismissal requirement is not met.

See dismissed during probation and can I appeal a probation dismissal? for the detail.

Challenging an unfair extension

Where an extension feels unjustified (no real reason, no clear objectives, a pattern of repeated extensions), the employer’s grievance procedure is the route to challenge.

A grievance letter should set out: the date the extension was confirmed, the reason given, why that reason is not legitimate, and what outcome you are asking for (confirmation of probation, reconsideration, removal of the extension).

Most employers respond to a grievance with a meeting and a written outcome within four to six weeks. Where the grievance succeeds, the extension may be lifted or shortened. Where it does not, the extension continues but the grievance record protects your position if a tribunal claim is eventually brought.

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Frequently asked questions

Can a UK probation period be extended?: Yes, where there is a legitimate reason. Common grounds: significant sickness absence preventing fair assessment, mandatory training not completed for reasons beyond the employee's control, performance concerns identified late requiring time to address, or reasonable adjustments needed for disability that affect the original timeline. The extension should be confirmed in writing with clear objectives.
How long is a typical probation extension?: Three months is the most common extension. Some employers use shorter (six to eight weeks) for specific limited concerns; some use longer (six months) for substantial development needs. The extension should be proportionate to the issue being addressed; an extension significantly longer than the underlying concern would justify can be challenged.
What are my rights during an extended probation?: The same rights as during the original probation: shorter contractual notice on both sides, statutory minimum notice once one month of service is complete, statutory holiday accrual, day-one rights (discrimination, whistleblowing, asserting a statutory right). The longer post-probation notice does not apply until the extended probation is confirmed.
Can I refuse a probation extension?: Not strictly; the extension is a unilateral employer decision under the contract. But you can challenge an unfair extension through the employer's grievance procedure. If the extension is being used as a pretext (for example, to delay confirmation while looking for a reason to dismiss), the grievance route is the way to flag this. In practice, accepting the extension and engaging actively is usually the better strategy.

General information about UK probation extensions. Specifics depend on your contract. For your situation, contact ACAS or an employment-law solicitor.