TL;DR: A dismissal is automatically unfair when the main reason is one the statute protects, such as pregnancy, whistleblowing, a health and safety concern or union activity, and for almost all of those reasons the employee needs no minimum service. The Employment Rights Act 2025 has already widened the list and the deadline for claims, and from 1 January 2027 it adds fire and rehire and removes the cap on compensation.
What makes a dismissal automatically unfair
Most unfair dismissal claims turn on two questions: did the employer have a potentially fair reason, and did it act reasonably in treating that reason as enough to dismiss? Automatically unfair dismissal in the UK skips the second question. If the reason, or the principal reason, is one that the legislation protects, the dismissal is unfair. A careful investigation, three hearings and an appeal do not change the outcome.
The other difference is service. Ordinary unfair dismissal needs a qualifying period of continuous employment. For nearly every automatically unfair reason, section 108(3) of the Employment Rights Act 1996 switches that requirement off, so a claim can follow a dismissal in week two. This guide covers Great Britain; Northern Ireland has its own legislation.
You will see articles promising "the 9 reasons" or "60 grounds". Neither number means much. The reasons are spread across the 1996 Act, the trade union legislation and several sets of regulations, and the count depends on how you group them. What matters is whether the reason in front of you is on the statutory list, and which compensation and relief rules come with it.
The full list as it stands in October 2026
These are the reasons that make a dismissal automatically unfair, grouped the way HR teams tend to meet them. Unless noted, none needs qualifying service.
Family and pregnancy. Under section 99 and the regulations made under it: pregnancy, childbirth or maternity; maternity, adoption, paternity, shared parental and parental leave; parental bereavement leave, neonatal care leave and carer's leave; time off for antenatal or adoption appointments; and time off for dependants.
Whistleblowing. Section 103A protects an employee dismissed for making a protected disclosure. The disclosure must be one the worker reasonably believes is in the public interest and tends to show a crime, a breach of a legal obligation, a danger to health or safety, environmental damage, a miscarriage of justice or a cover-up. Since 6 April 2026, section 43B also covers information showing that sexual harassment has occurred, is occurring or is likely to occur. Good faith is no longer a condition of liability. A tribunal can only use bad faith to cut compensation by up to 25%.
Health and safety. Section 100 covers designated safety representatives and committee members carrying out their role, employees raising a reasonable concern where there is no representative, and employees leaving or refusing to return to a place of serious and imminent danger, or taking steps to protect themselves or others from it.
Asserting statutory rights. Section 104 protects an employee who brings proceedings, or alleges that the employer has breached a statutory right. It does not matter whether the right exists or was actually breached, as long as the claim was made in good faith, and the employee does not need to name the right. Related sections protect action over the national minimum wage (104A), working time (101A), flexible working requests (104C), pension auto-enrolment (104D), requests for study and training (104E) and tax credits (104B).
Trade unions and industrial action. Under section 152 of the Trade Union and Labour Relations (Consolidation) Act 1992: union membership or non-membership, taking part in union activities or using union services at an appropriate time, and refusing an unlawful inducement to give up collective bargaining. Dismissal for taking part in protected industrial action is covered by section 238A of the same Act.
Representatives and office-holders. Employee representatives for redundancy and TUPE consultation (103), occupational pension scheme trustees (102), workforce representatives under the Working Time Regulations, and representatives under the information and consultation regulations.
Other protected reasons. Jury service (98B). Shop and betting workers who refuse Sunday work (101 and 101ZA). Being on a blacklist of union members (104F). Asserting rights under the Part-time Workers, Fixed-term Employees and Agency Workers Regulations. Political opinions or affiliation and reserve forces membership also remove the qualifying period, although they are not automatically unfair reasons in themselves.
Redundancy selection. Section 105 makes a redundancy dismissal automatically unfair where the employee was selected for one of the reasons above, even if the redundancy itself is genuine. A redundancy selection matrix cannot repair a selection that was driven by a protected reason.
Two traps in the list
A dismissal because of a TUPE transfer is automatically unfair under regulation 7 of the TUPE Regulations 2006. Regulation 7 is missing from the section 108(3) list, though, so the employee still needs the ordinary qualifying period.
Discrimination is the second. Many lists include it, but a discriminatory dismissal is a claim under the Equality Act 2010, with its own rules on proof. It also needs no minimum service and carries no cap on compensation, which is why claimants so often plead it alongside an unfair dismissal claim on the same facts.
What the Employment Rights Act 2025 has added or changed
The 2025 Act is commencing in stages. The government's implementation timeline, last updated 25 September 2026, and the commencement regulations give this picture.
| Change | Status at 6 October 2026 |
|---|---|
| Dismissal for protected industrial action: 12-week protected period removed | In force since 18 February 2026 |
| Disclosures about sexual harassment become protected disclosures | In force since 6 April 2026 |
| Tribunal time limit for most claims extended from three to six months | In force since 1 October 2026 |
| Fire and rehire and "fire and replace" become automatically unfair | Expected 1 January 2027 |
| Dismissal connected with a spent conviction needs no qualifying period | 1 January 2027 |
| Cap on the compensatory award removed for all unfair dismissal | 1 January 2027 |
| Further protection against dismissal during pregnancy and after family leave | Expected in 2027, detail to follow in regulations |
The industrial action change is already live. Under section 77 of the 2025 Act, dismissing someone for taking part in protected industrial action is automatically unfair however long the action lasts. Before 18 February 2026, protection was largely limited to the first 12 weeks.
Fire and rehire is the largest addition. Section 28 inserts new sections 104I and 104K into the 1996 Act. The Department for Business and Trade's factsheet explains the effect. Dismissing an employee for refusing a "restricted variation" will be automatically unfair: a cut in pay, a change to total hours, a reduction in leave, a pension change, or a shift-pattern change of a kind set out in regulations. So will dismissing employees to replace them with non-employees, such as agency workers, doing substantially the same work. The one exception is narrow. The employer must show that financial difficulties were affecting its viability or soon would, that the change was meant to deal with them, and that it could not reasonably have avoided making it. Changes to location or job role fall outside the automatic rule and are judged as ordinary unfair dismissal, with the tribunal told to weigh consultation and anything offered in return.
The spent convictions change comes from Schedule 3, which adds dismissals connected with a spent conviction to the section 108(3) list. Until 1 January 2027 that claim still needs two years' service.
How these claims arise in practice
Few automatically unfair dismissals start with a manager deciding to dismiss someone for whistleblowing. They start with a sequence. An employee raises something protected: a pregnancy, a safety complaint, a question about holiday pay, an email to the finance director about invoices. A few weeks later, concerns about their performance or attitude appear for the first time. Then a short-service employee is let go without much process, because "they haven't got two years".
That last assumption is the mistake. The qualifying period only blocks an ordinary unfair dismissal claim. It does nothing when the employee says the real reason was a protected one.
A published Employment Tribunal decision shows the pattern. In Hill v 9ine Accounting Ltd, the employee was dismissed shortly after telling her employer she intended to take maternity leave. The employer pointed to performance. The judge found that the performance issues had been "contrived" to give an excuse for ending her employment before her maternity leave began, and the section 99 claim succeeded alongside a pregnancy discrimination claim.
The evidence that decides the reason
The burden of proof depends on service. Where the employee has the qualifying service, the employer has to prove its reason. Where they do not, the employee has to show that the reason was a protected one. The tribunal in Hill set this out, citing the Court of Appeal in Smith v Hayle Town Council. In practice that offers less comfort than it sounds, because the tribunal decides the reason from timing and documents, and most of the documents are the employer's.
What tribunals look at:
- Timing. How close the dismissal sits to the protected act, and whether anything about the employee's performance or conduct was recorded before it.
- Who knew. Whether the person who made the decision knew about the disclosure, the pregnancy or the union activity. Handing the decision to a different manager helps only if that person worked from evidence the first manager did not shape.
- Contemporaneous records. Notes, appraisals and emails written at the time. A performance file that begins after a protected act reads as a file built for the purpose.
- Consistency. Whether others with the same record were treated the same way.
- What managers wrote to each other. Messages and chat threads are disclosable, and a casual remark about someone "causing trouble" after a grievance can decide the case.
So before any short-service dismissal, ask whether this person has done anything protected recently and who knows about it. Their length of service tells you very little.
What a successful claim costs
Compensation for unfair dismissal is a basic award, worked out like statutory redundancy pay, plus a compensatory award for actual financial loss.
Until 1 January 2027, the compensatory award is capped at the lower of £123,543 and 52 weeks' gross pay, the figures set by the Employment Rights (Increase of Limits) Order 2026 from 6 April 2026. Section 124(1A) already removes that cap for whistleblowing and health and safety dismissals, including redundancy selection for those reasons. Those two categories are the expensive ones today.
Some reasons also carry a minimum basic award of £9,157 regardless of service or salary: dismissals of health and safety representatives, working time representatives, pension trustees and employee representatives under section 120, and union-related dismissals under the 1992 Act.
From 1 January 2027, section 25 of the 2025 Act removes section 124 entirely, so no unfair dismissal compensatory award will be capped. For a senior employee on a long job search, that changes the numbers considerably.
Interim relief: the seven-day application
Interim relief is the remedy most HR teams have never met until it arrives. Under section 128, an employee dismissed for whistleblowing, as a health and safety or working time representative, as a pension trustee or employee representative, or for reasons connected with union recognition or blacklisting can apply within seven days of the effective date of termination. Union membership and activity dismissals have their own route under section 161 of the 1992 Act.
The tribunal hears it quickly. If it thinks the employee is likely to win and the employer will not reinstate or re-engage them, it orders the contract to continue. In practice that means paying the employee's salary until the full hearing, which can be many months away.
Respond to an application the day it arrives. The "likely to succeed" test is demanding, but your defence at that hearing is whatever evidence on the reason for dismissal already exists, because there is no time to build more.
How the 2027 changes shift the risk picture
From 1 January 2027 the qualifying period for ordinary unfair dismissal falls to six months, for any dismissal with an effective date on or after that day. The detail of that reform, and who it catches, is covered in our guide to the two-year rule and why it is changing.
For automatically unfair dismissal, the effect is mostly on who can claim and how. An employee past six months will be able to bring an ordinary unfair dismissal claim and plead the protected reason in the same claim, and the employer will then have to prove its reason. Once the cap goes, an uncapped award is no longer peculiar to whistleblowing and health and safety.
What does not change is the position of employees in their first six months. For them, an automatically unfair reason or discrimination remains the main way to challenge a dismissal. Dismissals in probation are where these claims cluster, which is why probation reviews need dates and written records whatever the length of service.
The time limit has also moved. For dismissals on or after 1 October 2026, Acas confirms the deadline is six months less one day, paused during early conciliation. A claim can now arrive much later than many HR teams expect.
A short check before any dismissal
Before a dismissal is confirmed, whatever the employee's length of service, someone outside the line management chain should be able to answer these:
- Has the employee done anything on the protected list in the last year? That includes complaints about pay, hours or safety, a pregnancy or leave request, a flexible working request, union involvement or a concern raised about wrongdoing.
- Does the decision-maker know about it, and is that recorded?
- Was the reason for dismissal documented before the protected act, or only after it?
- If this is a contract change, is it a restricted variation, and will the dismissal take effect on or after 1 January 2027?
- If the employee is a representative, trustee or whistleblower, is someone ready to respond to an interim relief application within days?
These questions usually surface first in a line manager's message to HR. Aura answers that kind of question from your own policies and UK employment law, and passes it to your HR team when it needs a judgement call. If a dismissal touches any of the reasons above, take employment law advice before it goes ahead. This article is general guidance and not legal advice.