The Harry Allen business was founded in 1945, just after the end of the war, by Harry Allen and his brother Frank as a wholesale business supplying new issues to the stamp trade. In 1960 the business was expanded to offer collectors a similar service, following the take-over of R.Roberts New Issue Service, originally founded in 1909 when Mr Roberts bought the Stanley Gibbons New Issue Service of the day.
As the traditional stamp market shrank Harry Allen grew by acquisition, taking over well-established businesses such as J Sanders which had been established over thirty years. Wholesale new issue services were also acquired including Charles McMiram & Co, M & N Haworth and most recently James Davis & Son .
In the early 1970s Harry Allen was amongst the first companies world-wide to enter the philatelic agency business when the company was appointed sales and distribution agents by the Swedish Post Office.
Harry Allen currently represent over 40 postal administrations world-wide, including the USA, Canada, Australia, New Zealand and Ireland, as well as acting as the exclusive distributor for CASCO Philatelic Services Ltd.