How to Dispute Your Three Mobile Bill

Finding an unexpected charge on your mobile bill can be frustrating, but you don't have to accept it. You have clear consumer rights when it comes to billing accuracy and service quality from your provider. This guide will walk you through the process of challenging incorrect charges on your Three Mobile bill.

Reviewed by Corey Musa, Founder·Last reviewed June 2026·LinkedIn

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Your rights

Under the Consumer Rights Act 2015, services, including your mobile phone contract, must be provided with reasonable care and skill. This means your billing should be accurate and transparent. If you believe Three Mobile has overcharged you, or failed to provide a service as agreed, you have the right to dispute these charges. If Three Mobile does not resolve your complaint to your satisfaction within 8 weeks, you can escalate your case to Ombudsman Services: Communications, an independent alternative dispute resolution scheme.

Step by step

1**Review your bill and gather evidence.** Carefully examine your Three Mobile bill, checking call logs, data usage, premium rate numbers, and roaming charges against your own usage records or expectations. Highlight the specific charges you dispute and note why.
2**Contact Three Mobile's customer service.** Call 333 from your Three phone, or 0333 338 1001 from any other phone. Clearly explain which charges you are disputing and why. Keep a record of the date, time, who you spoke to, and what was discussed.
3**Submit a formal complaint.** If customer service cannot resolve your issue, ask for their formal complaints procedure. Submit your complaint in writing (email or post), detailing your dispute, referencing your evidence, and stating your desired resolution. Mention your rights under the Consumer Rights Act 2015.
4**Escalate to the Communications Ombudsman.** If Three Mobile does not resolve your complaint within 8 weeks, or you receive a 'deadlock letter' (a final response you're unhappy with), you can take your case to Ombudsman Services: Communications. They are an independent body that can investigate your complaint and make a binding decision.

What they'll say, and your comeback

“Our records show this usage.”

Comeback, I have reviewed my own usage records, and they do not align with the charges on my bill. I require a detailed breakdown and evidence to support these specific charges, as I believe there has been an error in billing.

“It's part of your contract terms.”

Comeback, While I understand contract terms, I dispute this charge as either it was not clearly communicated, or it represents an unfair charge under the Consumer Rights Act 2015, which requires services to be provided with reasonable care and skill and billed accurately.

“We can't issue a refund for past usage.”

Comeback, I am disputing an incorrect charge, not seeking a refund for valid usage. Under the Consumer Rights Act 2015, I am entitled to a service that is billed accurately. If an error has occurred, I expect it to be corrected and any overpayment refunded.

FAQ

What if I've already paid the disputed bill?

You can still dispute the charges even if you've paid. If your dispute is successful, Three Mobile should refund the overcharged amount to you. Follow the same steps as if you hadn't paid.

How long does Three Mobile have to resolve my complaint?

Three Mobile has up to 8 weeks to resolve your complaint. If they haven't resolved it to your satisfaction within this timeframe, or if they send you a 'deadlock letter' before then, you are entitled to escalate your complaint to Ombudsman Services: Communications.

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A self-serve tool, not a law firm. General information, not legal advice.