"Is it illegal to record a conversation with someone in the UK without their permission?" asked The Sun newspaper recently, in an article which was generally sensible and accurate. But it had one significant error: it said, in respect of call recording by businesses "Under GDPR, consent to call recording must be actively be sought, following a clear explanation of why the call is being recorded". This simply isn't true – although the law dealing with recording of telephone calls is complex (blending data protection, human rights and interception issues), a specific statutory instrument (The Investigatory Powers (Interception by Businesses etc. for Monitoring and Record-keeping Purposes) Regulations 2018) exists which permits recording of calls by businesses for purposes such as staff training and development.
Consent of the caller or individual recipient of the call is not required (although the business must have made "all reasonable efforts" to inform participants that the call may be recorded). GDPR did not change this, and, to the extent that a legal basis under Article 6 of GDPR is required, it will normally be the case that the legitimate interests of the business apply.