Merryfield finally became a professional actor at the age of 57, after working for the Westminster Bank (later the National Westminster Bank) as a Senior Area Bank Manager for nearly 40 years, interrupted by his war Service. In contrast to his most famous character, Merryfield spent the war in the army, where his fine physique resulted in him being made a PT and jungle warfare instructor. It was during the war that he first discovered his love of acting when he served as an entertainments officer, putting on shows for the other troops. However, upon the end of the war, married and with his wife expecting a daughter, he opted to return to his job at the bank. At Natwest he rose through the ranks, and by the time of his early retirement, in 1978, he was a bank manager at the Thames Ditton branch in Surrey.