Complaint Letter to the Communications Ombudsman: Ofcom Guide

If your broadband, mobile or landline provider has ignored repeated complaints, billed you wrongly or failed to fix a service problem, a written complaint can finally get the issue on the record. A formal letter will not force Ofcom to investigate your individual case, but it will create a clear paper trail, prove that you have tried to resolve the matter, and set up the next step if escalation is needed.

This guide covers who actually handles telecoms complaints in the UK (it is not Ofcom in the way most people assume), when you can escalate to the Communications Ombudsman or CISAS, exactly what to include in your letter, and a template you can adapt for broadband, mobile, landline or pay-TV disputes.

Ofcom, the Communications Ombudsman and CISAS: Who Actually Handles Your Complaint

This is the part most consumers get wrong, and it costs them weeks. Ofcom is the regulator for the UK communications sector. It sets the rules, monitors providers and takes enforcement action where there are wider patterns of failure. Ofcom does not resolve individual customer complaints and will not award you a refund or compensation.

The bodies that resolve individual disputes are the two Ofcom-approved alternative dispute resolution (ADR) schemes:

Communications Ombudsman (Ombudsman Services: Communications)
CISAS (Communications and Internet Services Adjudication Scheme)

Every telecoms, broadband, mobile and pay-TV provider in the UK must belong to one of these two schemes. Which one your provider uses is set out in your contract terms and on their website. If you cannot find it, ask the provider directly or check Ofcom's published list of ADR memberships.

So the answer to "who do I write to" depends on the stage. To your provider first, then to the Communications Ombudsman or CISAS if it does not resolve the issue. Ofcom is the wrong target for an individual remedy, even though the phrase "Ofcom complaint" is what most people search.

For a broader view of how UK ombudsman schemes work across every sector, see our complete guide to writing a complaint letter to a UK ombudsman.

Before You Complain to the Communications Ombudsman

You almost always need to complain to the provider first. The Communications Ombudsman and CISAS both expect to see evidence that the provider has had a fair opportunity to put things right before they will accept the case.

The standard rule across telecoms is the eight-week trigger. If you have complained to the provider in writing and either:

eight weeks have passed without a final response, or
the provider has issued a deadlock letter (a written statement that it can do no more)

then you can refer the matter to the relevant ADR scheme. There is also a referral deadline (usually 12 months from the deadlock or final response date) so do not let the case go cold.

Keep everything in writing. Save the original letter, the provider's responses, complaint reference numbers, dates of calls and the name of any agent you dealt with. A posted letter is much harder for a provider to claim it never received than an email or a web form, especially in disputes that drag out.

When a Written Complaint Works Best

A written complaint is strongest when the problem has dragged on, the provider has fobbed you off, or you need a paper trail. This is common with billing disputes, missed engineer visits, poor mobile coverage, broadband faults, mid-contract price rises and problems cancelling a service.

A phone call may be quicker at the start, but it is harder to prove later. A formal letter gives you dates, wording and a clear statement of what outcome you want. That can make a real difference if the complaint later goes to deadlock or to the Communications Ombudsman.

Ofcom Complaint Letter Template

Use the wording below as a starting point and tailor it to your situation.

[Your full name] [Your address] [Postcode] [Email address] [Phone number]

[Date]

Complaints Department [Provider name] [Provider address]

Subject: Formal complaint regarding [account number / phone number / broadband account reference]

Dear Sir or Madam,

I am writing to make a formal complaint about the service I have received in relation to my [mobile / broadband / landline / pay-TV] account, reference [insert account number].

The issue is as follows: [give a short summary of the main problem].

The relevant background is:

On [date], [explain what happened]. On [date], [explain what happened next]. I contacted your customer service team on [date or dates] and spoke to [name or department if known]. Despite this, the issue remains unresolved.

As a result, I have experienced the following loss or inconvenience: [set this out clearly, for example loss of service, incorrect charges, missed appointments, inability to work from home, or time spent trying to resolve the matter].

To resolve this complaint, I am asking you to: [refund a charge / correct my bill / restore service / release me from contract without penalty / pay compensation / provide a written explanation].

Please treat this as a formal complaint and confirm your full response in writing within 14 days. If the matter is not resolved or eight weeks pass without resolution, I will refer the complaint to the relevant alternative dispute resolution scheme (Communications Ombudsman or CISAS).

I enclose or refer to the following supporting evidence: [list bills, screenshots, contract terms, complaint references, engineer appointment messages, or other documents].

Yours faithfully,

[Your name]

How to Adapt the Template to Your Case

The strongest version of this letter is the one that sounds specific, not copied and pasted. You do not need legal jargon. You do need facts.

If the problem is billing, focus on the exact charge, the date it appeared and why it is wrong. If the issue is service failure, explain how long the problem lasted, what support you were promised, and whether any appointments were missed. If the dispute is about cancellation, include the date you gave notice and how the provider responded.

Adjust the remedy to fit the issue. If you were overcharged, ask for a refund and account correction. If you have had prolonged disruption, ask for compensation as well. If trust has broken down completely, ask for release from the contract without early termination fees. The closer your requested outcome matches the problem, the harder it is to dismiss.

Common Telecoms Complaint Scenarios

The following are the disputes the Communications Ombudsman and CISAS see most often. The letter structure is the same, but the detail you include will differ.

Slow broadband speeds against advertised Include the speeds you were promised at sign-up, the speeds you are actually getting (screenshots from a recognised speed test, taken at consistent times), the dates you reported the issue, and any reference to the Ofcom Voluntary Code of Practice on broadband speeds where relevant.

Mobile signal failures and dropped calls Include the postcode where the signal is failing, the dates and rough times of failures, any coverage map promises made at sign-up, and details of any temporary fixes or signal boxes offered.

Mid-contract price rises Include the date you signed the contract, the original advertised price, the date you were notified of the rise, the new amount, and whether you were given a 30-day exit window. Ofcom rules on mid-contract price changes have tightened in recent years, so this is increasingly winnable.

Engineer no-shows and missed appointments Include the original appointment date and time, confirmation messages, who failed to attend, what the provider said afterwards, and what compensation (if any) was offered under the provider's automatic compensation scheme.

Early termination charges after cancelling Include the date you gave notice, the cancellation method (call, online, letter), the agent's name or reference number if applicable, the charge you are disputing and the contract end date you understood would apply.

Mis-sold contracts Include what you were told at sign-up versus what the actual terms turned out to be, any sales call recording references, and the date you became aware of the discrepancy. The provider must show you were given clear, accurate information at the point of sale.

What to Include as Evidence

Complaints move faster when the evidence is easy to follow. That does not mean attaching every document you have ever received; it means choosing the documents that prove the point.

Good evidence usually includes copies of bills, screenshots of online account pages, complaint reference numbers, emails, text messages about appointments, speed test results for broadband disputes, and a short timeline of calls. If you are arguing that a provider failed to honour what it promised, keep anything that shows the promise in writing. If it was only said on a call, note the date and time as accurately as you can.

Where people go wrong is sending a strong letter with no supporting detail. The complaint then becomes your word against theirs. Even a one-page timeline can make the file far easier to assess.

What Happens After You Send Your Letter

A complaint letter is not the final step. It is the start of a more credible process.

The provider should investigate and respond under its complaints procedure within 14 days, or at the latest within eight weeks. If it resolves the matter, that may be the end of it. If it does not, you will usually receive a deadlock letter, or eight weeks will pass without resolution, at which point you can take the case to the Communications Ombudsman or CISAS (whichever your provider belongs to).

Both schemes are free for the consumer. Both can direct the provider to refund charges, pay compensation, correct records, release you from contract or issue a formal apology. Their decisions are binding on the provider once you accept them.

If the ADR route fails or the matter falls outside its scope, the next step is usually a letter before action and, if necessary, a small claim through the county court.

Ofcom may still be worth contacting separately, not for individual remedy but to add your complaint to the data Ofcom uses to monitor provider behaviour. A high volume of complaints about a specific provider can trigger formal Ofcom investigations and market-wide action.

Common Mistakes to Avoid

The biggest mistake is writing as if Ofcom itself will order a refund the moment it sees your complaint. That is not how the system works, and misunderstanding it can lead to weeks of delay.

Another common problem is making the letter too broad. If your complaint includes six separate issues gathered over two years, the provider may struggle to identify the real dispute. Keep the letter focused on the key failure and the outcome you want. Background context is fine, but do not bury the point.

It is also a mistake to threaten court action or regulatory escalation too early unless you are genuinely ready to follow through. A firm but measured tone usually works better than a dramatic one.

Before You Send the Letter

Check whether the provider has a dedicated complaints address or process. Many firms accept complaints by post and online, but a physical letter carries more weight, especially in drawn-out disputes. It is harder to ignore, and easier to rely on later if you need to show that a formal complaint was made.

Keep a copy of what you send. If the matter is serious, tracked delivery is sensible because it gives you proof of posting and delivery. That matters if the provider later says it did not receive the complaint.

How PostRight Helps

PostRight generates a formal complaint letter from your inputs, includes the right structure for your case, and prints and posts it via Royal Mail from £1.99. For complaints that may end up at the Communications Ombudsman or CISAS, the Royal Mail Tracked 24 upgrade at £9.99 gives you proof of service.

If you already know what you want to say, you can upload a PDF and we will print and post it. If you need help structuring the letter, our complaint letter generator walks you through the right questions for telecoms disputes.

Frequently Asked Questions

Does Ofcom investigate individual customer complaints? No. Ofcom is the regulator for UK communications and uses complaints data to monitor provider behaviour at a market level. Individual disputes are handled by the two Ofcom-approved ADR schemes, the Communications Ombudsman and CISAS. Reporting an issue to Ofcom is still worthwhile because it informs broader enforcement, but it will not deliver you a personal remedy.

Who is the Communications Ombudsman? The Communications Ombudsman, formally known as Ombudsman Services: Communications, is one of the two Ofcom-approved ADR schemes for telecoms disputes in the UK. It is free for consumers, independent of the providers it covers, and its decisions are binding on the provider once you accept them. It handles broadband, mobile, landline and pay-TV complaints.

What is the difference between the Communications Ombudsman and CISAS? Both are Ofcom-approved ADR schemes for telecoms disputes and offer broadly similar services and remedies. The difference is which providers are members of each scheme. Some providers belong to the Communications Ombudsman, others to CISAS. You cannot choose; you must use whichever scheme your provider has signed up to. Your provider must tell you which one.

How do I know which ADR scheme my provider belongs to? Check your contract terms or the provider's website. Most list their ADR scheme in their complaints handling code or on a dedicated complaints page. If you cannot find it, ask the provider directly and they must tell you. Ofcom also maintains a list of provider memberships you can check.

How long do I have to complain to the Communications Ombudsman? You can refer a case once eight weeks have passed since your written complaint to the provider, or once the provider has issued a deadlock letter, whichever comes first. The referral deadline is usually 12 months from the deadlock or final response date, so do not delay once you have the right to escalate.

Can the Communications Ombudsman make my provider pay compensation? Yes. If the ombudsman upholds your complaint and you accept the decision, the provider is bound by it. The remedy can include refunds, compensation for distress and inconvenience, correction of records, release from contract without penalty, or a written apology. Compensation amounts vary by case but the scheme has the power to direct meaningful sums where the impact justifies it.

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The strongest telecoms complaints are calm, factual and difficult to argue with. If your provider has got something wrong, a clear letter that names the failure, the impact and the remedy you want gives you a much stronger footing than another frustrated phone call ever will.