After the 1902 registration in NSW, the No.1 branch (Newcastle) withdrew from the association and became the Newcastle (NSW) Master Builders Association. This organisation continues to retain close liaison with the Master Builders Association of NSW.
Historical records of registration are confusing as, despite the withdrawal of the Newcastle branch in 1902, it was not until 5 December 1922 that the Industrial Commission of NSW noted that the “Newcastle Branch, The Master Builders Association of NSW” was registered as an industrial union.
On 24 October 1918, during the final year of World War I, the St George Branch of the MBA was registered as an industrial union of employers; Central Cumberland Branch was registered on 30 December 1920.
Other builders associations were created as the need arose. To further the interests of builders in the suburbs, the Suburban Master Builders Association was established in 1920. Eastern Suburbs Master Builders Association and Manly-Warringah Master Builders Association were established in 1939. During the Second World War (1939-1945), these two groups liaised with the Suburban Master Builders Association and in 1945, formed the Council of Suburban Master Builders Associations (CSMBA). At this time, the Suburban Master Builders Associations name was altered to Canterbury-Bankstown Master Builders Association. That council conducted a campaign to form other suburban associations. By 1953, there were nine member associations throughout the metropolitan area of Sydney.