A contractor must include the NHS number of a registered patient as the primary identifier in all clinical correspondence issued by the contractor which relates to that patient.

The requirement in paragraph (1) does not apply where, in exceptional circumstances outside of the contractor's control, it is not possible for the contractor to ascertain the patient's NHS number.

In this regulation—

• “clinical correspondence” means all correspondence in writing, whether in electronic form or otherwise, between the contractor and other health service providers concerning or arising out of patient attendance and treatment at practice premises including referrals made by letter or by any other means; and

• “NHS number”, in relation to a registered patient, means the number, consisting of ten numeric digits, which serves as the national unique identifier used for the purpose of safely, accurately and efficiently sharing information relating to that patient across the whole of the health service in England.