Send Letters Online
To complain about a phone or internet provider, explain the service problem, dates, previous contacts and remedy you want through its complaints procedure. If it remains unresolved, identify the provider's independent dispute-resolution scheme before writing an escalation letter.
Phone, mobile, telecommunications, broadband and internet complaints are related searches, not necessarily separate ombudsman organisations. The correct route depends on your provider and the issue. Do not send the same personal documents to multiple schemes hoping one will accept the case.
Start with your provider's complaints process
Use the contact route in the provider's published complaints code. Include your account reference, affected phone number or service address, and the date you first reported the problem. Ask it to record the matter as a complaint and provide a reference. Keep a copy of the complaint and its acknowledgement.
Our formal complaint letter template helps with this first-stage message. Describe the outcome you want, such as an explanation of charges, restoration of service, correction of an account or consideration of a justified refund. A request is not a guarantee that the provider or scheme must grant that outcome.
Communications Ombudsman, CISAS or Ofcom?
Check the provider's complaints code and Ofcom's current ADR information to find whether it belongs to Communications Ombudsman or CISAS. Membership matters: you cannot choose either scheme solely because you prefer its name. Check that your account and the type of dispute are eligible too.
Ofcom regulates communications services and uses complaints to inform its work, but it is not the ADR adjudicator deciding your individual phone or broadband case. Reporting a problem to Ofcom is different from submitting an eligible case to the provider's ADR scheme.
Six weeks, eight weeks or earlier deadlock?
For complaints first raised on or after 8 April 2026, the normal unresolved-complaint ADR waiting period is six weeks. Complaints first raised before that date normally retain the eight-week period. A written deadlock response can allow earlier escalation. Follow the relevant scheme's current rules and referral deadlines.
Keep proof of your first complaint date. A new follow-up does not necessarily mean the dispute began that day, and calling your own letter a “deadlock letter” does not make it one. The provider issues the final response. Read our guide to deadlock and final responses if you are unsure what its reply means.
Build evidence around the actual service problem
- Broadband speed or reliability: dated fault reports, relevant test results, appointment records and the terms or service information you rely on. Explain how you tested rather than treating one screenshot as conclusive.
- Mobile or landline service: dates and locations of problems, affected numbers and support references. Distinguish coverage complaints from an account or device fault.
- Billing or cancellation: disputed invoices, payment dates, cancellation confirmation and the provider's explanation of charges.
- Switching or number transfer: the agreed dates, confirmations, delays and contacts with each relevant provider.
Keep dated call notes and copies of emails and webchats. Summarise long records in a timeline and attach only the useful documents. Redact unrelated account information where appropriate. Never include passwords, authentication codes or complete payment-card details.
Example phone or broadband ADR complaint letter
[Your name and contact details] [Date] To: [Provider's confirmed ADR scheme] Re: Unresolved complaint about [provider], account [reference] I first complained to the provider on [date], reference [reference]. I believe this complaint is eligible because [applicable waiting period has expired / the provider issued deadlock on date]. The problem is [specific service, billing or switching issue]. Key events: [dates, fault references and relevant provider responses]. The provider's proposed resolution is [accurate summary]. The points still unresolved are [brief list]. I ask you to consider [specific remedy], for these reasons: [facts]. I attach [relevant evidence] and the final response, if available. Please confirm whether you can consider the complaint. Yours faithfully, [Your name]
Check eligibility before using the example. Our communications complaint letter template offers editable wording for phone, mobile, broadband and internet disputes. Address it to the confirmed scheme, not automatically to Communications Ombudsman.
Submit your case without assuming a compensation entitlement
Use the scheme's official submission instructions and retain its case number. Describe actual financial loss or disruption, explain the remedy requested and distinguish it from any offer already made. Automatic compensation arrangements, where applicable, have specific qualifying conditions; not every inconvenience or service fault creates a payment entitlement.
If posting documents, verify the recipient's current address and allow for delivery before deadlines. Posting evidence does not itself establish eligibility, prove the facts of a dispute or confirm that the scheme has accepted the case.
Free ADR and an optional physical letter
Consumer ADR is free. Accepted online complaint routes do not require a postal purchase or paid representative. Send Letters Online is independent of Ofcom and both ADR schemes. If you prefer physical correspondence, you can write, print and post a letter online from £2.99, subject to the final checkout quote. We provide printing and postage, not dispute adjudication or legal advice.
