Unfair vs Constructive Dismissal in the NHS

These two terms are used interchangeably online, and mixing them up can cost you a claim. This guide explains the difference using ACAS and GOV.UK guidance, shows how the law is changing in January 2027, and gives NHS-flavoured examples. It does not tell you whether you would win: that depends on your facts and evidence, so talk to your union or a solicitor.

Side by side

Unfair dismissal

GOV.UK says a dismissal is likely to be unfair where, for example, you asked for flexible working, refused to give up working time rights, joined a trade union or took legal industrial action, took jury service or family leave, or exposed wrongdoing (whistleblowing). ACAS says fair reasons include misconduct and capability, and that the employer should still follow a fair procedure. GOV.UK also lists redundancy, a legal restriction on employing you, and "some other substantial reason" among the reasons an employer may rely on.

So there are two questions: was there a fair reason, and was the procedure fair? A genuine conduct reason can still be an unfair dismissal if the investigation, hearing or sanction was unreasonable. Our guides to the disciplinary process and the capability procedure set out the steps an NHS employer is expected to follow, and how to appeal an NHS dismissal explains the internal route you should usually try first.

Constructive dismissal

ACAS describes constructive dismissal as when an employee resigns because of a serious breach of contract by their employer. GOV.UK says it happens when you are forced to leave your job against your will because of your employer's conduct, and that the breach may be one serious incident or a series of incidents serious when taken together. ACAS lists examples:

• Regularly not being paid the agreed amount without good reason.
• Being bullied or discriminated against.
• Raising a grievance that the employer refuses to look into.
• Making unreasonable changes to working patterns or place of work.

GOV.UK adds not paying you or suddenly demoting you for no reason, forcing you to accept unreasonable changes to how you work, and allowing harassment or bullying. Note that you have to resign for it to be a constructive dismissal, and the claim is a hard one to establish. Employers can argue there was no breach, or that you did not resign because of it. See NHS suspension explained for how a prolonged, unexplained suspension can feed into arguments of this kind.

How the service rules are changing

Per ACAS, protection from unfair dismissal becomes a right after six months in a job, from January 2027, and the commencement regulations (SI 2026/559, regulation 3) bring section 25 of the Employment Rights Act 2025 into force on 1 January 2027. Transitional rules tie the change to the effective date of termination. The same table is on our Dismissal Guidance Advisor, and the Employment Rights Act 2025 guide shows the wider timeline. For staff in the first months of a job, see NHS probation periods explained.

Examples in an NHS setting

These are invented illustrations to show how the two claims differ. They are not predictions, and every real case turns on its facts.

In both, the employee would still need to show the legal test is met, and the employer would put its side. A tribunal decides, and many disputes resolve at or before ACAS conciliation without a hearing.

Before you resign

• • Talk to your union or get legal advice first. It is the single most useful step, and ACAS recommends it.
• • Raise it in writing informally and then through the grievance procedure. See the NHS grievance procedure.
• • Keep a dated record of what happened and your attempts to resolve it. For bullying, use the diary in our evidence diary guide.
• • Check what the contract says about the term you say was breached (pay, hours, place of work).
• • Do not sign a settlement agreement without advice: ACAS notes it prevents a later constructive dismissal claim.
• • Look at the money: notice, final pay, pension and benefits. See notice periods.
• • Note the dates: your resignation date or end of notice starts the tribunal clock, and you must notify ACAS within the limit.

Time limits

You normally need an ACAS early conciliation certificate before a tribunal claim, and the time limit applies to notifying ACAS. Per ACAS, most claims arising on or after 1 October 2026 have 6 months minus 1 day, and before that date 3 months minus 1 day. For unfair dismissal the clock runs from your effective date of termination (for a constructive dismissal, the end of your notice, or your resignation date if no notice is given). Raising a grievance or appeal does not extend it.

Related guides

This page is general information about unfair and constructive dismissal, drawn from ACAS and GOV.UK guidance and legislation.gov.uk, correct to the best of our knowledge as of October 2026. Employment law is changing through 2026 and 2027. It is not legal, HR or employment advice and does not replace your union's advice or specific legal advice. FrontlinePay is an independent site and is not affiliated with, or endorsed by, ACAS, GOV.UK, any NHS trust, NHS England or any trade union.