Unfair Dismissal UK: Your Rights and the 2027 Change

Most employees need two years' continuous service before they can bring an unfair dismissal claim, but that qualifying period is falling to six months from 1 January 2027 under the Employment Rights Act 2025. Some dismissals, however, are unfair from an employee's very first day.

What Counts as Unfair Dismissal

Under Part X of the Employment Rights Act 1996, a dismissal is unfair unless the employer can show it was for one of five potentially fair reasons and that the decision, and the process followed, fell within the "band of reasonable responses" a reasonable employer might take. A tribunal does not simply ask whether it would have dismissed the employee; it asks whether this employer's decision was one a reasonable employer could have reached, given the reason and the procedure used. A fair reason on its own is not enough. Where an employee resigns in response to a fundamental breach of contract, that can instead amount to constructive dismissal, and where the stated reason is conduct, the fairness of the process often turns on whether the employer properly treated the matter as gross misconduct justifying dismissal without notice.

The Qualifying Period: 2 Years, Falling to 6 Months from 1 January 2027

To bring an ordinary unfair dismissal claim, an employee currently needs two years' continuous service with their employer. The Employment Rights Act 2025 shortens that qualifying period to six months, with the change taking effect from 1 January 2027. This is a reduction in the length of service required, not a move to a day-one right; employees who have not yet reached the new six-month threshold when it comes into force will generally still be unable to bring an ordinary unfair dismissal claim. Employees dismissed before 1 January 2027 are assessed against the two-year rule in force at the time of their dismissal. The reform sits alongside a wider set of Employment Rights Act 2025 changes phased in across 2026 and 2027, including statutory sick pay, redundancy pay uprating, and a new Fair Work Agency enforcement body.

Automatically Unfair Reasons That Need No Qualifying Service

A separate category of dismissal is automatically unfair regardless of length of service, because no qualifying period applies at all. These day-one protections exist because certain reasons for dismissal are treated as unacceptable whatever the employee's tenure.

These grounds are separate from the qualifying-period reform above and do not depend on it. An employee dismissed for whistleblowing on their first day at work can already bring a claim, before or after the 2027 change alike.

The Five Potentially Fair Reasons for Dismissal

Where an employee does have the necessary qualifying service, an employer defending an unfair dismissal claim must show the real reason for dismissal falls within one of five categories set out in the Employment Rights Act 1996.

A fair reason alone does not make a dismissal fair. The employer must also follow a reasonable procedure, which typically means an investigation, a hearing, and a right of appeal appropriate to the circumstances.

Remedies: Reinstatement, Re-engagement and Compensation

A tribunal that finds a dismissal unfair can order reinstatement (the employee returns to their old job) or re-engagement (a comparable job with the same employer), though both are rare in practice; compensation is the usual outcome. Compensation has two elements. The basic award is calculated using the same formula as statutory redundancy pay: age-banded weeks of pay for each full year of service, capped at 20 years and at a maximum week's pay of £751. The compensatory award covers the employee's actual financial loss, such as lost earnings and benefits, and currently sits under a statutory cap. That cap is being removed from 1 January 2027 under the Employment Rights Act 2025, alongside the shortened qualifying period. Tribunals can also reduce either award, for example where the employee contributed to their own dismissal.

Time Limits and ACAS Early Conciliation

An unfair dismissal claim must currently reach an employment tribunal within three months less one day of the effective date of termination, extending to six months from 1 October 2026 for dismissals on or after that date, under the Employment Tribunal (Extension of Time Limits) (Miscellaneous Amendments and Transitional Provisions) Regulations 2026. Before filing, the employee must first notify ACAS and go through Early Conciliation, which is mandatory for most tribunal claims and pauses the clock while conciliation is attempted. Missing the deadline, even by a day, usually means the tribunal has no power to hear the claim, so anyone intending to claim should contact ACAS well before the applicable window closes. There is no fee to bring a claim, following the Supreme Court's ruling in R (UNISON) v Lord Chancellor [2017] UKSC 51, which struck down the previous fee regime. For a fuller look at the process itself, including the time-limit extension, see our guide to the employment tribunal.

Northern Ireland: A Separate but Similar Framework

Northern Ireland legislates unfair dismissal separately from Great Britain, through its own employment legislation with near-identical substance. Claims are heard by the Industrial Tribunal (and, for religious or political discrimination, the Fair Employment Tribunal) rather than the Employment Tribunal, and the enforcement body is the Labour Relations Agency (LRA) rather than ACAS. NI legislates separately and may not adopt the same timetable as the 1 January 2027 qualifying-period change; anyone employed in Northern Ireland should check current rules directly with the LRA rather than assume the GB reform date applies.

For the full picture of UK employment rights, see our UK employment law hub, part of our wider guide to United Kingdom law.

This article is general information about unfair dismissal law in Great Britain, not legal advice. Employment law changes, and individual circumstances vary; consult ACAS, Citizens Advice, or a qualified solicitor before acting on your specific situation.