A customer compliance manager (CCM), formerly known as a customer relationship manager (or CRM), is a senior professional appointed by HMRC for businesses dealt with by the Large Business Service (LBS) and for a selection of businesses dealt with by Local Compliance (Large and Complex) (L&C). LBS customers have a turnover of £600 million or above, or assets of £2 billion or more. An L&C customer is a business with turnover of £30 million or more or with more than 250 employees.

Generally, a CCM is allocated when the turnover of the business exceeds £200 million. Where there is no CCM for an L&C business, a customer coordinator will be appointed. Guidance regarding the CCM and customer coordinator roles can be found on the GOV.UK website.