The union's branches dealt with issues relating to members at a local level. Branches formed (and closed) in response to the need for representation in towns / areas, with over 70 branches being in existance at various times. The branches were closed in 2004 as part of a wider reorganisation of the union's structure.
"The first branch was formed in Dundee on 8 June 1893, and by the end of its first year the Union had 1,093 members with branches in Glasgow, Liverpool and Newcastle-on-Tyne. Membership continued to grow, reaching 2,421 by the end of 1894, with a further seventeen branches forming, mainly in cities in Scotland, the North of England and the Midlands."
From: Players' Work Time, A History of the British Musicians' Union, Williamson, J. & Cloonan, M. (p. 41)