If you're unhappy with a CMC's response to your complaint, get in touch with us.

Get in touch by phone

Call our consumer helpline:

  • 0800 023 4567 (free to call on mobiles or landlines)
  • (18002) 020 7964 1000 (calls using next generation text relay)
  • +44 207 964 1000 (if you're calling from abroad)

Get in touch online

You can tell us about your complaint online

Get in touch by post

Exchange Tower, Harbour Exchange, London, E14 9SR
CMC complaint form (PDF)

Get in touch by text

Text us on 07860 027 586

Please don't send any account numbers or bank details by text, we'll sort that out later. Text messages will be charged at your network's standard rate.

Our business advice desk

If you're a CMC business and you'd like to speak to us, you can contact our business advice desk.