How to complain about your provider

Last reviewed: 2026-03-04

When to complain

You have grounds to complain if your phone provider has:

• Migrated your line without proper notice or your consent
• Failed to check whether you rely on a telecare alarm or other life-safety device before switching your line
• Left you without phone service for an extended period during the migration
• Lost your phone number during a switch or port
• Failed to provide the battery backup or alternative they promised for power cuts
• Given you incorrect information about what would happen during the change
• Charged you for services they did not deliver

This is not an exhaustive list. If your provider has not met the standard you were promised, or has not followed Ofcom's rules, you can complain.

Step 1: Complain to your provider

Start with your provider's own complaints process. Every provider is required to have one.

• Call their customer service number or use their online complaints form.
• Be specific about what went wrong and what you want them to do about it.
• Ask for a reference number and keep it.
• Follow up in writing (email is fine) so you have a record.

Your provider should acknowledge your complaint and give you a response within eight weeks.

Step 2: Escalate to an ADR scheme

If your provider has not resolved your complaint within eight weeks, or if they have sent you a "deadlock letter" (a letter saying they cannot resolve it), you can escalate to an independent Alternative Dispute Resolution (ADR) scheme.

There are two ADR schemes for telecoms in the UK. Your provider will be a member of one of them:

• CISAS (Communications and Internet Services Adjudication Scheme), run by CEDR. www.cedr.com/consumer/cisas
• Ombudsman Services: Communications, www.ombudsman-services.org

You can check which scheme your provider belongs to on the Ofcom website or by asking your provider directly.

The ADR scheme will review the evidence from both sides and make a decision. If you accept the decision, it is binding on the provider. If you do not accept it, you can still take the matter to court (though this is rarely necessary).

What evidence to keep

Throughout the process, keep records of:

• Dates and times of phone calls with your provider (and the name of the person you spoke to if possible)
• Reference numbers for complaints and engineer visits
• Copies of emails and letters
• Screenshots of account pages showing the problem
• Bills that show incorrect charges
• A note of any dates you were left without phone service
• If relevant, confirmation from a telecare provider that your alarm was affected

Phrases that may help

When speaking to your provider or writing a complaint, these specific references can be useful:

• "I understand Ofcom requires you to check for vulnerable customers and telecare users before migrating a line."
• "I was not given adequate notice before my line was changed."
• "I would like to escalate this to your formal complaints procedure."
• "Please send me a deadlock letter so I can refer this to your ADR scheme."
• "I have been without phone service for [number] days and I would like compensation in line with Ofcom's automatic compensation scheme."

Ofcom's role

Ofcom does not handle individual complaints, but it does monitor complaints data and can take enforcement action against providers that are not meeting their obligations. If you believe your provider is systematically failing customers during the migration, you can report this to Ofcom at ofcom.org.uk/make-a-complaint.

Automatic compensation

Under Ofcom's automatic compensation scheme, some providers must pay you automatically if they leave you without service, miss an engineer appointment, or fail to start your service on the agreed date. Not all providers have signed up to this scheme, but most major ones have. Check with your provider or on the Ofcom website.