How to Write a Letter to Acas About an Employment Dispute UK
- James Pite
- 1 day ago
- 8 min read
If you have a dispute with your employer and are considering making an employment tribunal claim, you will need to contact Acas before you can do so. This is not optional for most types of claim. It is a legal requirement. The process is called early conciliation, and it exists to give both sides a chance to resolve the dispute without going to tribunal.
This guide explains what Acas does, why early conciliation matters, what you need to tell Acas, how to write to them, what happens during the process, and what to do whether the matter settles or does not. It also covers the significant change made in December 2025, which extended the early conciliation period from six weeks to 12 weeks.
What Acas Is and What It Does
Acas stands for the Advisory, Conciliation and Arbitration Service. It is a government-funded, independent body whose purpose is to help employers and employees resolve workplace disputes. It does not take sides. It does not tell either party what the outcome should be. Its role is to act as a neutral facilitator, helping both sides understand each other’s position and explore whether a settlement is possible without formal legal proceedings.
Acas offers several services, including a confidential helpline (0300 123 1100), free online guidance on employment rights, and early conciliation, which is the formal pre-tribunal process. This guide focuses on early conciliation, which is the route most people need when they have a serious workplace dispute they want to resolve or escalate.
Why You Need to Contact Acas Before Going to Tribunal
Under the Employment Tribunals Act 1996, most employment tribunal claims cannot be submitted until the claimant has notified Acas and gone through the early conciliation process, or confirmed they do not wish to conciliate. If you skip this step, the tribunal will reject your claim. As Acas’s own guidance on early conciliation confirms, the types of claim that require early conciliation include unfair dismissal, constructive dismissal, discrimination, harassment, equal pay, wrongful dismissal, unlawful deduction of wages, redundancy pay disputes and breach of contract claims.
There are some limited exemptions, including certain whistleblowing cases and some collective disputes, but for the vast majority of employees with a workplace grievance that has not been resolved, early conciliation is a mandatory first step.
Important: the tribunal time limit clock does not stop just because you are thinking about contacting Acas. For most claims you have three months minus one day from the date the problem occurred to notify Acas. Once you do notify Acas, the clock pauses during the early conciliation period and for a set time after it ends. Do not delay in contacting Acas if you are considering a tribunal claim.
The December 2025 Change: Early Conciliation Now Lasts Up to 12 Weeks
From 1 December 2025, the early conciliation period was extended from six weeks to 12 weeks, under The Employment Tribunals (Early Conciliation: Exemptions and Rules of Procedure) (Amendment) Regulations 2025. This doubled the time available for Acas to help parties reach a settlement. For cases notified to Acas on or after 1 December 2025, early conciliation can now last up to 12 weeks, though it can end earlier if both sides agree there is no prospect of settlement or if a settlement is reached before the period expires.
This change gives more time for complex or sensitive disputes to be resolved, but it also means the overall pre-tribunal process takes longer. If you are considering a claim, factor this into your planning.
What to Tell Acas: The Notification Form
The early conciliation process starts with an early conciliation notification form, which you submit online via the Acas early conciliation page. You can also call Acas on 0300 123 1100 and they will complete the form for you over the phone.
The notification form only requires a small amount of information at the outset. You do not need to describe your dispute in detail. You need to provide:
Your full name and contact details
Your employer’s name and address (use the correct legal name, including Ltd or Limited if it is a company)
Whether you want to try early conciliation or want to decline and receive a certificate immediately
That is genuinely all that is required at the notification stage. You do not need to detail your grounds, state what compensation you want or provide any documents at this point. All of that comes later if conciliation takes place.
Do You Need to Write a Letter or Can You Use the Online Form?
For most people, the online notification form or phone call is the most efficient way to start early conciliation. However, there are situations where writing a letter to Acas is appropriate or preferable:
You are unable to use the phone or online services due to disability, health or access issues
You want a written record of your notification date for your own records
You are writing to your Acas conciliator during the conciliation process to clarify your position or update them on developments
You want to put your settlement position in writing to your conciliator for them to communicate to the employer
You are writing to withdraw from conciliation or to request your certificate
The sections below cover both how to notify Acas by letter if needed, and how to write to your conciliator during the process.
Letter One: Notifying Acas of an Employment Dispute
[Your full name]
[Your address]
[Your email and telephone]
[Date]
Early Conciliation Team
Acas
Euston Tower, 286 Euston Road, London NW1 3JJ
Subject: Early Conciliation Notification – [Your name] v [Employer’s full legal name]
Dear Sir or Madam,
I am writing to notify Acas that I am considering making a claim to the Employment Tribunal against my employer, [employer’s full legal name], whose registered address is [employer’s address].
I wish to take part in early conciliation.
My contact details are as follows: [name, address, telephone, email]. Please contact me by [preferred method] in the first instance.
[If you need to notify Acas that you cannot use the phone: I am unable to communicate by telephone due to [reason, e.g. hearing impairment / severe anxiety / disability]. Please communicate with me by email only at [email address].]
I confirm that the date on which I became aware of, or the date of, the act or omission giving rise to my potential claim was [date], which falls within the relevant time limit.
Yours sincerely,
[Your name]
[Signature]
Letter Two: Writing to Your Acas Conciliator During the Process
Once Acas assigns you a conciliator, you will have a named point of contact for the duration of the early conciliation period. You can write to them to clarify your position, update them on any developments, set out what settlement you would accept, or ask them to put a specific proposal to the employer.
Keep any written communication with your conciliator factual and focused. The conciliator is impartial and will share what you say (with your consent) with the employer. Do not write anything in a letter to your conciliator that you would not be comfortable with the employer seeing.
Conciliation is confidential to the outside world but not between the parties.
Example: setting out your settlement position to your conciliator
[Your name]
[Your address]
[Date]
[Conciliator’s name]
Acas
Subject: Early Conciliation Reference [number] – [Your name] v [Employer]
Dear [Conciliator’s name],
Thank you for your communication of [date]. I am writing to set out my position and what I would require to settle this dispute without proceeding to tribunal.
Background
[Provide a concise, factual summary of the dispute. Focus on the key facts: what happened, when, what the employer did or failed to do, and the effect on you. Keep this to a few paragraphs. You do not need to present a legal case at this stage.]
What I am seeking
[Describe clearly what you want in order to settle. This might include: a financial payment of £[amount] representing [lost wages / compensation for discrimination / notice pay / holiday pay outstanding] / a written reference in the terms I have set out / an agreed statement for announcement purposes / confirmation that no negative information will be shared with future employers / an apology / reinstatement to my role on the same terms as before.]
I am willing to engage constructively with the conciliation process and to consider reasonable proposals from the employer. Please communicate my position to [employer] and let me know their response.
Yours sincerely,
[Your name]
[Contact details]
What Happens During Early Conciliation
Once your notification is received and you agree to conciliate, Acas will assign a conciliator and contact your employer. The employer cannot be forced to take part but most do. According to Acas’s own statistics, around 71 percent of cases that reach conciliation settle without going to tribunal. As Acas explains on its how early conciliation works page, the conciliator speaks to both sides separately, helps identify what each party wants, and tries to find common ground. They cannot impose a settlement. They cannot tell either party what the outcome should be. They can tell you whether your expectations appear realistic based on their experience.
If a settlement is reached, it is recorded in a legally binding document called a COT3. Once you and the employer agree to a COT3, you are bound by it even if you have not signed it yet. Read it carefully and get advice before agreeing if you are unsure. A COT3 settlement usually means you cannot take the matter to tribunal afterwards.
If no settlement is reached within the 12-week early conciliation period, Acas will issue you with an early conciliation certificate. You then have a set period, which depends on where you are in the original time limit calculation, to submit your tribunal claim. The certificate number must be included on your tribunal claim form.
What to Do If Early Conciliation Does Not Resolve Your Dispute
If the employer refuses to engage, or the conciliation period ends without a settlement, do not be discouraged. The early conciliation certificate you receive is what you need to proceed to tribunal. Submit your tribunal claim promptly using form ET1, available online. Include your early conciliation reference number. Get advice on the strength of your case before submitting if you are not certain.
You can also choose not to engage in conciliation at all and simply request the certificate immediately. This is your right. Acas cannot force you to conciliate. If you want to go straight to tribunal without attempting conciliation, tell Acas you do not wish to conciliate when you make your notification and they will issue the certificate.
Getting Help
Acas’s helpline (0300 123 1100) provides free, confidential guidance on your employment rights and what you can expect from the early conciliation process. Free advice on whether your dispute is likely to succeed at tribunal and how to present your case is available from Citizens Advice, whose guidance on early conciliation covers the full process from notification to tribunal claim. If your dispute involves potential discrimination, whistleblowing or constructive dismissal, getting specialist legal advice before the conciliation period begins is strongly recommended. Many employment solicitors offer a free initial consultation. If you want help drafting a clear, well-structured settlement position letter to your conciliator, the team at LetterLab can help you set out what you want in a way that supports productive conciliation.
Key Facts at a Glance
For most employment tribunal claims, notifying Acas is a legal requirement before you can submit a claim
You have three months minus one day from the date of the problem to notify Acas for most claim types
The early conciliation period is now up to 12 weeks for cases notified on or after 1 December 2025
The notification form only requires your name, address and your employer’s name and address
You do not have to engage in conciliation. You can request the certificate immediately if you prefer
Around 71 percent of cases that reach conciliation settle without going to tribunal
A COT3 agreement is legally binding once both sides agree to it, even before signing
If conciliation fails, your early conciliation certificate number goes on your ET1 tribunal claim form
The Acas helpline is 0300 123 1100 and is free and confidential
The Key Takeaway: Contact Acas Early, Know What You Want, Engage Constructively
Early conciliation is both a legal requirement and a genuine opportunity. The majority of cases that go through it settle without the time, cost and stress of a tribunal hearing. That outcome depends on both sides engaging with realistic expectations, and on you being clear about what you need in order to settle.
Contact Acas as early as possible within your time limit. Know what you want before the conciliation starts. Communicate your position to your conciliator clearly and in writing. And if the conciliation does not produce a result, your certificate is ready and your tribunal claim can proceed.
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