Midlothian and East Lothian have become the latest councils to introduce a shared service model for their education and children's departments.
In March, Stirling and Clackmannanshire announced their plans for joint education and social services, which they said heralded a new way of working for local government in Scotland.
Earlier this week, Midlothian and East Lothian came up with a slightly different blueprint for the phasing in of shared services.
Separate meetings of each council have endorsed plans to bring together the central management and operational support services for education in a single integrated structure.
The move will mean the appointment of a joint head of education. But while there will be a phased approach towards formal shared services, the authorities will retain independent governance arrangements reflecting the "distinct nature and context of each council area".
"The aim is to improve service delivery and reduce costs. Both councils face similar challenges in providing services for an increasing number of children and young people, with the population of children in Midlothian set to rise by 26.5 per cent over the next 20 years, and the projection for East Lothian being a 37 per cent rise," said a spokesman for both councils.
The leader of East Lothian Council, Paul McLennan, said the new partnership arrangement gave East Lothian and Midlothian "the opportunity to be at the forefront of public-sector reform in Scotland".
Midlothian leader Derek Milligan said: "This is an important step in ensuring the quality of education and children's services is maintained.
"It will allow us to cut management costs and protect frontline services. Our priority now is to recruit the new head of service so they can begin the job of making shared services in this area a reality."
In March, Stirling and Clackmannanshire councils appointed Belinda Greer from Stirling as head of joint education services and Deirdre Colliers from Clackmannanshire as head of joint social services. Their respective councils take a lead authority role for that service area, and each head directs the staff and manages the service across both councils.