Regulated by Ofcom

How to complain to Three

Mobile complaints tend to be about annual price rises inside a fixed term, charges for data or roaming that were not made clear, handsets that fail inside the warranty, and difficulty leaving. Ofcom rules cover the price rise and the switch. The Consumer Rights Act covers the handset.

Where to send a Three complaint

These details are published by Three itself. Sending a complaint to the route the company actually operates, rather than a general enquiries address, is the single cheapest thing you can do to speed it up.

Official complaints page: https://www.three.co.uk/terms-conditions/code-of-practice/customer-complaints-code
Complaints address: Three Customer Complaints, Hutchison 3G UK Ltd., PO Box 333, Glasgow, G2 9AG
Their published response time: 14 days — quote this back to them if it passes.
Who they escalate to: CISAS — the scheme Three names on its own complaints page. Sending a case to the wrong scheme wastes weeks.

Worth knowing: Three acknowledges non-finance complaints by text message before investigating, and runs two parallel procedures split by whether the complaint concerns device financing.

The rights that apply when you complain to Three

Three is a UK mobile network, so the rules below are the ones that decide your complaint. Each is named, because a letter that cites the specific rule is handled by a different team to one that does not.

An in-contract price rise must have been set out in pounds and pence before you signed. If it was not, the rise is a contractual modification and you can exit without an early termination charge. Ofcom General Conditions C1.14 to C1.17, with price transparency rules in force from 17 January 2025
You can switch away using a PAC to keep your number or a STAC to leave without keeping it, obtained by text, and the provider must not charge you notice-period fees for a period after you have left. Ofcom General Condition C7, switching and number portability
A handset sold with the contract must be of satisfactory quality, fit for purpose and as described. Your claim for a faulty handset is against the network that sold it, not the manufacturer. Consumer Rights Act 2015, sections 9 to 11
Where a handset is bought on credit alongside the airtime, the credit agreement is separate and may be regulated, which affects your cancellation and early settlement rights. Consumer Credit Act 1974
You have a 14-day cancellation right on anything bought online, by phone or at your door, running from delivery of the handset. Consumer Contracts (Information, Cancellation and Additional Charges) Regulations 2013

Three complaints line: 0333 338 1001 — put the complaint in writing as well. A phone call leaves no record you can rely on later.

The deadlines that decide your claim

30 days — the short-term right to reject a handset

If the handset is faulty within 30 days of delivery you can reject it outright for a full refund, rather than accepting a repair. After 30 days the network gets one attempt at repair or replacement first.

6 months — the burden of proof

A fault appearing within six months of delivery is presumed to have been there from the start. The network has to prove otherwise, not you.

6 weeks — when ADR opens up

Six weeks after your first complaint, or on a deadlock letter, you can take the case to the network’s alternative dispute resolution scheme. Ofcom cut this wait from eight weeks to six with effect from 8 April 2026.

What to put in the letter to Three

Complaints teams work from a script. The detail below is what moves a case off that script and onto the desk of someone who can authorise a remedy.

The tariff name and the exact price you were quoted at sign-up, with the contract summary if you have it.
For a billing dispute, the specific line items you are challenging rather than the total, with dates.
For a handset fault, the date of delivery, the date the fault appeared, and every repair attempt so far.
What you want: the charge removed, the handset replaced or refunded, or release from the contract with no early termination charge.

If Three says no, or says nothing

Escalate to the Communications Ombudsman or CISAS.

When you can go: Eight weeks after your first complaint, or as soon as you get a deadlock letter.

How long you have: 12 months from the deadlock letter or from the eight-week point.

What it costs: Free to you. The provider pays the case fee.

Whether it binds Three: Binding on the provider if you accept the decision.

Worth knowing before you start

Networks belong to one of the two Ofcom-approved schemes, and not all to the same one. Check Ofcom’s list, or ask the network which scheme covers you, before you file.

Common questions

My network raised my monthly price mid-contract. Do I have to accept it?

Only if the rise was set out in pounds and pence at the point of sale. Ofcom required that from 17 January 2025. Contracts that instead promised a rise linked to inflation, or an unspecified annual increase, do not meet the standard, and a rise under them is a contract modification to your detriment. General Condition C1 then gives you a penalty-free exit. Ask in writing, quote C1, and ask for a PAC so you keep your number.

My phone broke after eight months. Is that the network’s problem or the manufacturer’s?

The network sold it to you, so under the Consumer Rights Act the network is the one on the hook. A manufacturer warranty sits on top of your statutory rights and does not replace them. Past six months you may have to show the fault was inherent rather than caused by damage, but the network cannot simply refer you to the manufacturer and close the case.

I was charged hundreds for data I did not know I was using. Can I get it back?

Ask for the itemised data records and check whether the network applied the spend caps and out-of-bundle warnings it is required to offer. Where a network failed to warn you, or applied roaming charges without the notification you should have had, the charge is challengeable. Put it in writing, ask for the charge to be removed while it is investigated, and escalate to ADR at six weeks.

Can I cancel a contract I signed in a shop?

The 14-day cancellation right in the Consumer Contracts Regulations covers distance and off-premises sales, which means online, telephone and doorstep. A contract signed in a shop is an on-premises sale and does not carry that automatic right, although many networks give a short returns window voluntarily. Check the network’s own returns policy, which is contractual and enforceable.

Where this comes from

Every rule on this page is drawn from primary legislation, a regulator, or an approved dispute resolution scheme. Check them yourself.

Paybacker is not a law firm and this is not legal advice. It is a summary of the published rules that apply to a mobile network, so that you can put your own case properly. For a dispute of real value, or anything turning on facts unique to you, speak to a solicitor or Citizens Advice.

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