Constructive Dismissal Guide UK — What It Is & How to Claim
What constructive dismissal is, what counts as a fundamental breach of contract, how to resign and claim, time limits, and how much compensation you could receive.
·5 min read
If your employer makes your working life unbearable, you may be able to resign and claim constructive dismissal. Here’s how it works.
What Is Constructive Dismissal?
Element
Detail
Definition
You resign because your employer has fundamentally breached your contract
Legal treatment
Treated as a dismissal by the employer (not a voluntary resignation)
Legal basis
Employment Rights Act 1996, Section 95(1)(c)
Qualifying service (ordinary)
2 years continuous employment
Qualifying service (discrimination/statutory right)
None — protection from day one
What Counts as a Fundamental Breach
Category
Examples
Pay
Significant pay cut, withholding wages, removing contractual benefits without consent
Role and status
Demotion, removing responsibilities, undermining your position
Working conditions
Major change to hours, location, or duties without agreement
Bullying and harassment
Persistent bullying that the employer fails to address
Health and safety
Employer fails to provide a safe working environment
Trust and confidence
Any conduct seriously undermining the employment relationship
Discrimination
Treating you unfairly because of a protected characteristic
Failure to investigate
Not properly addressing your grievance or complaint
Suspension without cause
Suspending you without reasonable grounds
The “Last Straw” Doctrine
Feature
Detail
What it is
A relatively minor incident that is the final event in a series of breaches
Key requirement
The “last straw” must contribute to the breach — it needn’t be serious on its own
Example
Months of undermining behaviour, then a dismissive response to your grievance
Important
The last straw must not be entirely trivial or innocuous
Three Requirements for a Successful Claim
Requirement
Detail
1. Fundamental breach
Your employer must have committed a serious breach of your contract (express or implied terms)
2. Resignation in response
You must resign because of the breach (not for another reason like a new job)
3. No undue delay
You must resign promptly after the breach — waiting too long suggests you accepted it (“affirmation”)
What Is Affirmation?
Factor
Impact
Continuing to work without protest after the breach
Suggests you accepted the breach
Raising a grievance first
Does NOT amount to affirmation — you can grieve and then resign
How long is too long?
No fixed rule — but weeks/months of continuing without protest is risky
Signing a new contract with changed terms
Usually amounts to acceptance
Steps to Take
Step
Action
1
Document everything — keep records of incidents, emails, dates, witnesses
2
Raise a formal grievance first — this strengthens your position and doesn’t count as accepting the breach
3
Take legal advice — speak to ACAS, a union, or an employment solicitor before resigning
4
Resign clearly — state in your resignation letter that you’re resigning because of your employer’s conduct and identify the breach(es)
5
Contact ACAS for early conciliation within 3 months minus 1 day of your resignation
6
Submit ET1 claim to the employment tribunal if conciliation doesn’t resolve it
Resignation Letter
Your resignation letter should include:
Element
What to write
Statement of resignation
“I am resigning from my position with immediate effect”
Reason
“I am resigning because of your fundamental breach of my contract of employment”
The breach(es)
Briefly describe what your employer has done — reference the specific conduct
Grievance reference
Mention any grievance you raised and the outcome
Reservation of rights
“I reserve my rights to bring a claim for constructive unfair dismissal”
Important: Do not include anything that undermines your claim (e.g. “I’ve found a new job” or “I’m leaving for personal reasons”). Keep it factual and professional.
Time Limits
Action
Deadline
Contact ACAS for early conciliation
3 months minus 1 day from your resignation date
Submit ET1 claim form
Within 1 month of the ACAS certificate (if conciliation doesn’t resolve it)
Extension possible?
Only in exceptional circumstances — don’t rely on this
Compensation
Basic Award
Element
Calculation
Formula
Same as statutory redundancy pay
Per year of service (age under 22)
0.5 week’s pay
Per year of service (age 22–40)
1 week’s pay
Per year of service (age 41+)
1.5 weeks’ pay
Maximum weekly pay
£700 (2025/26)
Maximum years
20
Maximum basic award
~£21,000
Compensatory Award
Element
Detail
What it covers
Loss of earnings, future loss, loss of statutory rights, expenses
Cap (ordinary unfair dismissal)
Lower of 52 weeks’ gross pay or £115,115 (2025/26)