The Charity Finance Directors' Group (CFDG) has recruited its 1,000th member.
The organisation, which was launched in 1987, has grown significantly over the past five years and now has three regional groups, as well as its main London-based membership.
In tandem with its growth in members and the increasing importance of finance in charity accountability, the CFDG has become an important voice in influencing the Government and other bodies.
The 1,000th member is Keith Ward, finance director of the City and Guilds of London Institute. He said: "I've worked exclusively in the commercial sector until now and realise that there are significant differences."
Paul Breckell, chair of the CFDG board, said that the group's success showed how much charity professionals appreciated help in keeping track of their charity finances and reporting.