This part of GOV.UK is being rebuilt – find out what beta means

HMRC internal manual

Specialist Investigations Operational Guidance

Introduction and organisation: recording information: communicating by telephone

It is often very useful and quick to discuss matters over the phone. However in order to preserve confidentiality you must make sure you are speaking to the correct person. All HMRC cases are subject to rules relating to confidentiality (see SIOG6300 for further information on confidentiality) but SI cases, by their nature, are particularly sensitive. You must make a typed note of your telephone conversations as soon as possible after they end and retain any hand written notes in the file for evidential purposes should the case become contentious or get referred to CI.