The short answer
Complaining about broadband in the UK is a two-stage process. First you complain to your provider, using its own complaints process. If that doesn't sort things out, you can take the dispute to an independent alternative dispute resolution (ADR) scheme, often just called "the ombudsman". Ofcom, the communications regulator, requires every provider that serves households to belong to one, and using it costs you nothing.
You can go to ADR once six weeks have passed since you first complained, or sooner if your provider sends you a deadlock letter saying it can't do any more. The six-week wait applies to complaints first raised on or after 8 April 2026; before that date it was eight weeks.
This is general information rather than advice on your own case, checked in October 2026.
Before you complain: get your evidence together
Both ADR schemes decide on the evidence in front of them, and CISAS says plainly that it won't gather evidence for you. So get organised before you pick up the phone.
Both schemes ask for broadly the same things:
- Written contact: emails, letters, webchat transcripts and texts. Save or screenshot webchats before you close them, as Citizens Advice suggests.
- Call notes: the date, time and name of the person you spoke to, and what they said or promised. Start a simple log now and keep it going.
- Bills and bank statements, especially if the complaint is about money.
- Evidence of the problem and of your attempts to get in touch, such as screenshots, fault reference numbers and phone records.
Getting call recordings
If an important promise was made on the phone, you can ask the provider for the recording with a subject access request (a request for the personal data a company holds about you). Companies must answer within one month, which can be extended by two months for complex or multiple requests. CISAS advises waiting until you have the recordings before you open a case, because once a claim has been made it can't be put on hold while you gather evidence. That's a good reason to ask early.
Keep paying what you don't dispute
It's tempting to stop paying while you argue, but don't. The Communications Ombudsman doesn't recommend cancelling Direct Debits or refusing to pay during a dispute, because of problems such as a default on your credit file. CISAS says a provider may carry on chasing a debt while a case is open, and Citizens Advice notes you could face late-payment charges if you withhold money and your dispute fails. Keep paying the undisputed part and argue about the rest.
Step 1: complain to your provider properly
Neither ADR scheme will accept a dispute your provider hasn't had the chance to put right, so this step can't be skipped. Ofcom's rules (General Condition C4 of the conditions every provider must follow) set out how providers have to handle it, which gives you some useful leverage.
Find the provider's complaints code
Every provider must have a Customer Complaints Code: a short document explaining how to complain, how it investigates, how long that takes, and which ADR scheme it uses. Under the rules it should be reachable within one or two clicks of the provider's homepage, mentioned in its terms and conditions, and available free in hard copy or an accessible format if you reasonably ask.
The code tells you the routes you can use. Providers must offer at least a phone number (free or charged at geographic rates), a UK postal address, and an email address or web form for complaints. They must also train staff to recognise a complaint, and keep you informed about how it will be investigated and how long that should take, the outcome, and the ADR scheme's details. When you get in touch, say clearly that you're making a complaint and ask for it to be logged and handled under the provider's complaints code, so there's no doubt about when the clock started.
If you're not sure which company actually supplies your broadband, for example because it came bundled with something else, our broadband providers hub lists the providers we cover and links to a page on each.
What to put in your complaint
Put the main complaint in writing so you have a dated record. Citizens Advice suggests a written complaint about a bill includes your name, address, contact number and account number, a copy of the bill, and exactly which charges are wrong. The same structure works for any broadband complaint. If you post a letter, send it recorded delivery and keep proof of postage.
Be clear about what you want. The Communications Ombudsman's own tips include being clear about how you'd like the problem fixed and complaining as soon as you notice something is wrong.
Example wording you can adapt (a template, not a real case):
"I am making a formal complaint about [the problem]. My account number is [number]. Since [date], [what has happened, in two or three sentences]. I contacted you on [dates] and was told [what was said or promised]. To put this right, I would like [a refund of £X / a credit / the fault fixed by a date / to leave my contract without an exit fee]. Please give me a complaint reference number and tell me which ADR scheme you belong to."
Get a reference and note the start date
Ask for a complaint reference number and write down the date you first complained. That date starts the six-week clock, so it matters later. If you hear nothing, chase. The Communications Ombudsman lists chasing an unresponsive provider and noting each contact among its tips. If the first person can't help, ask for the complaint to be escalated in line with the provider's code. Some codes spell out the escalation path: Zzoomm's, for example, goes to its Head of Customers and then its Chief Commercial Officer, while WightFibre's goes to its complaints team, then its Customer Service Manager, who will bring it to the chief executive's attention if you're still not satisfied.
Most complaints never get as far as an ombudsman. Ofcom said that, across January 2022 to 2024, 79% of complaints to the biggest telecoms companies were resolved in under a week and 94% within six weeks. Even so, around 700,000 consumers still had a complaint open at six weeks, which is the gap ADR exists to fill. If you want to see how providers compare on complaints before you start, our guide to checking a broadband provider's complaint figures explains where those numbers come from.
The six-week rule and deadlock letters
There are two ways to get to ADR. Whichever comes first opens the door.
Situation | When you can go to ADR |
|---|---|
Complaint first raised on or after 8 April 2026 | Six weeks after you first told your provider |
Complaint first raised before 8 April 2026 | Eight weeks after you first told your provider |
Provider sends a deadlock letter | Straight away, whatever the date |
Example: if you first complained on 1 May, six weeks later is 12 June. From that day you can go to the ombudsman if it's still unresolved, even if the provider is still "looking into it".
The six-week wait applies whichever of the two schemes your provider uses. Some providers' complaints codes and help pages still mention eight weeks (we found several in October 2026), so don't be put off if yours does. The Communications Ombudsman and CISAS both state the six-week rule for complaints raised since 8 April 2026.
What a deadlock letter is
A deadlock letter is a letter or email in which the provider says it can't do anything more to resolve your complaint. It's sometimes titled "final response" rather than "deadlock". It should tell you that you can now take the dispute to the ADR scheme, and it lets you do that immediately, without waiting out the six weeks. Virgin Media, for example, says it will send a letter or email confirming you can refer an unresolved complaint to ADR free of charge.
If a provider tells you on the phone that it won't budge, ask it to confirm that in writing.
Don't leave it too long
Both schemes say you must bring the dispute within 12 months of receiving a deadlock letter. The Communications Ombudsman says it can't review a dispute brought later than that. CISAS's Scheme Rules (April 2026) exclude applications received more than 12 months after you got the deadlock notice, unless you and the provider both agree to extend it; if the notice came by post, the 12 months starts three working days after it was sent, unless there's evidence you received it on a different date.
Even without a deadlock letter, don't let a complaint drift: recordings and your memory of what was said are easier to pin down while the problem is fresh.
Which ADR scheme covers your provider?
Ofcom approves two ADR schemes:
- CISAS (the Communication & Internet Services Adjudication Scheme), run independently by CEDR, the Centre for Effective Dispute Resolution.
- The Communications Ombudsman, which was called Ombudsman Services until July 2023. Some providers' documents still use the old name.
Your provider belongs to one or the other, and you can only use that one. The table below shows what we found. It's based on providers' own complaints codes and terms, CEDR's list of CISAS members and, where we had nothing newer, Ofcom's ADR checker (June 2025 version), checked October 2026. Memberships change, so confirm in your provider's complaints code.
Provider | ADR scheme | Where we found it |
|---|---|---|
BT, EE, Plusnet | Communications Ombudsman | Ofcom ADR checker (June 2025) |
Utility Warehouse | Communications Ombudsman | Utility Warehouse's complaints help page |
Sky, NOW, TalkTalk, Vodafone | CISAS | Ofcom ADR checker (June 2025); CEDR's list |
Three | CISAS (see note below) | Three's complaints code; CEDR's list |
CISAS (see note below) | Virgin Media's complaints page; CEDR's list | |
Zen Internet | CISAS | CEDR's list |
POP Telecom, Hey!Broadband, 4th Utility, Rise Fibre, Truespeed | CISAS | Providers' complaints codes and terms |
V4 Consumer, Hyperoptic, Quickline, YouFibre, Voneus, WightFibre, Zzoomm, Rebel Internet | Communications Ombudsman | Providers' complaints codes and terms |
A note on Three and Virgin Media: Ofcom's June 2025 checker listed both under the Communications Ombudsman, but their own complaints pages and CEDR's list of companies now name CISAS. Three's code adds that a complaint about the financing of a device goes to the Financial Ombudsman Service instead, with CISAS for everything else. Go by what your provider's current complaints code and deadlock letter say.
Smaller providers vary too, so don't assume. POP Telecom belongs to CISAS, while V4 Consumer says complaints it can't sort out within six weeks can go to the Communications Ombudsman. Both provider pages note the scheme.
How to check which scheme your provider uses
The order matters, because the older lists aren't always current.
- Read your provider's complaints code first. It must name the scheme and give its contact details, and it's the provider's own current statement. Your deadlock letter, if you get one, should name it too.
- Search for your provider on each scheme's website. The Communications Ombudsman says that if your provider isn't on its site you may need CISAS, and CISAS says a provider that isn't a member may belong to the Communications Ombudsman.
- Use Ofcom's ADR checker as a cross-check, which Ofcom and Citizens Advice both point to. Bear in mind the version we could see (June 2025) was out of date for at least Three and Virgin Media, so if it disagrees with the provider's code, go by the code and the scheme's own list.
A June 2026 National Audit Office report on the water, energy and broadband regulators (as reported by ISPreview) found that consumers in those sectors are often not directed to the relevant dispute resolution service. If your provider hasn't told you its scheme, ask it to put the answer in writing.
How the Communications Ombudsman handles a dispute
Once the six weeks have passed or you have a deadlock letter, the Communications Ombudsman's process runs like this:
- Register the dispute online, by phone, by email or by post. Its phone lines are open Monday to Friday, 8am to 6pm, and its 03 numbers cost no more than a call to an 01 or 02 number.
- Look at any early offer. Under what it calls Facilitated Complaint Resolution, the provider may make an offer to settle. Some providers acknowledge fault and resolve the dispute within a few days at this stage. You don't have to accept.
- Evidence. If no offer is accepted, both sides give their evidence within 14 days.
- Decision. The ombudsman reviews the case and tells both sides its decision.
- Putting it right. If you accept the decision, the provider has 28 days to carry out the remedy.
The Communications Ombudsman says most disputes are resolved in under six weeks on average. You don't need a lawyer, though you can get independent advice or have someone represent you.
It won't take a case if you've already accepted an offer as settling the matter, asked a court to deal with it, or had it considered by another ADR scheme, or if it judges the dispute frivolous or vexatious. However, if you accepted a fix from your provider and the problem wasn't solved, came back or new issues arose, it can still look at it.
How CISAS handles a dispute
CISAS uses adjudication: an independent adjudicator decides the case on the written evidence. Its process:
- Apply online through its "New case" form, with an application form sent by email or post, or by phone (Monday to Friday, 9am to 5pm).
- Eligibility review. CISAS checks the complaint is one it can deal with.
- Provider's response. The provider responds to your claim and you get the chance to comment on what it says.
- Settlement or decision. The provider may make a settlement offer, and accepting it ends the case. Otherwise an adjudicator with a legal background makes a decision.
- Accept or reject. You have 30 working days from when the decision is sent to tell CISAS whether you accept it in full or reject it. You can't accept part of it, and you can't accept it once that time has run out. If you don't clearly accept it, it isn't binding on either side.
- Compliance. If you accept, the provider must carry out what the decision says within 20 working days of CISAS telling it you've accepted, and CISAS reports non-compliance to Ofcom.
Ofcom requires more than 90% of CISAS cases to get a decision within six weeks of being accepted. CEDR's own overview puts the whole process at roughly six to eight weeks. Submit your application once your evidence, including any call recordings, is complete. The adjudicator's decision is final: under CISAS's rules it can't be reviewed or appealed, and evidence sent in after it's issued won't be considered.
What the ombudsman can and can't do
It helps to know what a realistic outcome looks like before you start, so you can ask for something the scheme can actually give.
What you can get
- Practical action: correcting a charge, a refund or account credit, cancelling a contract without penalty, or fixing a service problem.
- An apology and, for the Communications Ombudsman, recommendations to the provider.
- A financial award for inconvenience. The Communications Ombudsman says a typical "Time & Trouble" award is £50 to £100. CISAS says awards for inconvenience and distress are typically no more than £100 to £200 in total.
Both schemes cap the total at £10,000, including refunds, credits, waived charges and any award. The cap is a ceiling rather than a guide to what you'll get, so it's worth being realistic: the typical inconvenience figures above are modest.
Limits on what it can do
- No fines. The Communications Ombudsman says it can't punish providers, issue fines or dictate how they operate. Its job is to put your dispute right, not to regulate.
- Your own costs. ADR is free to use, but CISAS's rules say each side pays its own costs, and neither can claim them from the other, including the cost of legal representation.
- Some subjects are out of scope. CISAS can't deal with where a pole or mast is placed, wiring inside your home, the content of adverts, a company's decision about whether to offer a product, or fraud. The Communications Ombudsman can't look at streaming services such as Netflix or Amazon Prime, or mis-sold consumer credit, which goes to the Financial Ombudsman Service.
Is the decision binding?
Only on the provider, and only if you accept it. Under both schemes you're free to reject the decision and pursue the matter another way, such as through the courts. The two differ in the detail:
- Communications Ombudsman: you can withdraw your dispute at any point. In a limited number of circumstances, such as new evidence or a material error, you may be able to appeal.
- CISAS: you can withdraw at any point before the decision, but once the final decision is issued you can only accept or reject it. You must accept within 30 working days or the decision can't be accepted at all, and there's no appeal.
So if CISAS sends a decision you're happy with, accept it promptly: silence doesn't count as a yes.
Common broadband complaints and where to start
Some problems have their own rules worth knowing first.
- Wrong bills and unexpected charges. Billing is a common source of disputes: the National Audit Office's June 2026 report on the water, energy and broadband regulators found it a consistent cause of complaints to dispute resolution services across those sectors. Our guide to disputing a wrong broadband bill covers what to check and what to do about a debt you don't think you owe.
- Faults and compensation that didn't arrive. Providers signed up to Ofcom's automatic compensation scheme (BT, EE, Hyperoptic, Plusnet, Sky including NOW, TalkTalk with some restrictions off the Openreach network, Utility Warehouse, Virgin Media, Vodafone and Zen) should credit you without you asking. If you believe you're owed compensation and haven't had it, Ofcom says to raise it with your provider and then go to ADR, and the Communications Ombudsman says it can decide whether you were entitled. Our automatic compensation guide explains what's covered.
- Problems switching or leaving. If the problem is a delayed switch, paying two providers at once or an exit fee you think is wrong, our guide to fixing broadband switching problems covers what to do at each stage, and our guide on how to cancel broadband covers giving notice and final bills.
- Reward cards and sign-up offers that never turned up. Check the offer's terms for any claim deadline or conditions before you complain. Our guide to broadband reward card claims walks through it.
- Accessibility and support needs. You're entitled to the complaints code free in an accessible format on reasonable request. If you need extra support to complain, our guide to broadband help for disabled customers explains what to ask for.
After the complaint: staying or switching
If a complaint leaves you wanting a fresh start, and either the ombudsman lets you leave without an exit fee or your contract has ended anyway, it's worth seeing what else is available before you sign up again.
You can use the comparison on our cheap broadband deals page to see live deals available at your postcode, provided by our comparison partner. We don't switch you ourselves or take sides in your dispute. Before you commit to a new provider, it's worth looking up which ADR scheme it uses and reading its complaints code, so you know the route if anything goes wrong.
Broadband complaint FAQs
How long do I have to wait before going to the broadband ombudsman?
For a complaint you first raised on or after 8 April 2026, you can go to your provider's ADR scheme six weeks after you first told the provider. If you first complained before that date, the wait is eight weeks. Either way, you can go straight away if the provider sends a deadlock letter.
What is a deadlock letter?
It's a letter or email from your provider saying it can't do anything more to resolve your complaint. It may be called a "final response". It lets you take the dispute to the ADR scheme immediately, without waiting six weeks. Under both schemes you must do so within 12 months of receiving it.
Should I use CISAS or the Communications Ombudsman?
You don't get to choose: you use whichever scheme your provider belongs to, and its complaints code must name it. As of October 2026, BT, EE and Plusnet use the Communications Ombudsman, while Sky, TalkTalk, Vodafone, Three and Virgin Media use CISAS. Memberships change, so check your provider's current code.
Does it cost anything to use the broadband ombudsman?
No. Both Ofcom-approved schemes, CISAS and the Communications Ombudsman, are free for household customers, and you don't need a lawyer. CISAS's rules add that each side pays its own costs, so if you choose to pay for legal help you can't claim that back from the provider.
Should I stop paying my broadband bill while I complain?
Generally no. The Communications Ombudsman advises against cancelling Direct Debits or refusing to pay, because of the risk of a default on your credit file. CISAS says providers can keep chasing debts during a case. Pay the undisputed part and dispute the rest in writing.
How much compensation can the ombudsman award?
Both schemes can award up to £10,000 in total, including refunds, credits and waived charges. Awards for inconvenience are much smaller: the Communications Ombudsman says £50 to £100 is typical, and CISAS says inconvenience and distress awards are typically no more than £100 to £200.
Do I have to accept the ombudsman's decision?
No. A decision only binds your provider if you accept it, and you're free to reject it and go to court instead. With CISAS you must accept within 30 working days of the decision being sent, or it lapses. Once accepted, the provider must act within 28 days (Communications Ombudsman) or 20 working days (CISAS).
