Competition and Markets Authority
The Competition and Markets Authority's Cartels Hotline is available for handling data protection enquiries and reporting data misuse. Callers can ask questions about personal data processing, data subject rights, and compliance under UK GDPR and DPA 2018. The hotline also accepts complaints about data misuse by the CMA. It is recommended to call during operating hours for a direct response. Written requests may be preferred for clarity and record-keeping. If calling, specify that your enquiry is for the Data Protection Officer to avoid being routed to general enquiries.
Updated 15 Dec 2025
Expected outcomes
- Handle data protection enquiries
- Report data misuse
- Ask about data subject rights
- Inquire about GDPR compliance
- Submit data protection complaints
Call preparation
Assemble everything before you dial. These requirements are verified by our call analysts and updated as organizations change their scripts.
- Full name
- Contact details
- Enquiry details
- Proof of identity
- Incident description
- Relevant dates
- Supporting evidence
Known issues
Some callers experience difficulty reaching the Data Protection Officer directly, often being routed through a general switchboard. To improve the likelihood of a direct response, clearly mention 'Data Protection Officer' in your request. Persistence may be necessary. If possible, consider sending a detailed email to the DPO for record-keeping and clarity. This approach can help ensure your concerns are addressed promptly and accurately.
