After leaving Welshpool Grammar School, Peter Jeffreys read History at UCW Aberystwyth and subsequently obtained a postgraduate certificate in education at London University. He taught in grammar schools in Kent and Bedfordshire before appointment as the deputy divisional education officer for St Albans. Subsequently he served as an assistant education officer with the then Cardiff County Borough Council and while there was awarded the degree of M.Ed at Cardiff University. After serving as a senior assistant secretary at the Open University he moved to Buckinghamshire County Council as the Senior Assistant Education Officer for General Services. Prior to retirement he served initially as the Secretary and Registrar of the Hatfield Polytechnic and then following the acquisition of university status in the same role at the University of Hertfordshire.
Appointed a member of the Council of the Honourable Society in 2002, he served as the Honorary Secretary of the Society between 2009 and 2015. His other interests include local history research and as an active actor and singer with the Company of Ten, a St Albans based amateur dramatic society,