Shortened to GBOS, the society was founded in 1970 and is a study group for the stamps and postal history of the regions and occupation post offices abroad that used the stamps of Great Britain and were overprinted for use. The society continues to explore the ways in which, and reasons why, British stamps and other postal material have been overprinted for use outside the UK or for special functions within the UK.

These specialist areas include, GB Departmental issues, BOIC (British Occupation of Italian Colonies), Morocco Agencies, Gulf States, The Levant and the Bechuanalands.

The Society can offer support and knowledge on these collecting areas of interest in a friendly and informal way whether you are an experienced collector or just looking to branch out into a new area. We welcome new members.