Kingston, Merton, Richmond and Sutton councils have been given £485,000 by the Government as reward for saving money through merging services.
The four authorities will share the “transformation challenge” grant, using it to go further in sharing services.
Last May Kingston and Sutton merged their IT departments, while all four boroughs joined their legal teams together after a vote last February.
The move was expected to save £600,000 over four years.
In 2012 communities and local government secretary Eric Pickles encouraged councils to club together to buy services in a letter containing 50 cost-cutting suggestions.
This week Kingston and Richmond launched the joint children’s services company, Achieving for Children, after three years of planning.