Barnet LBC has voted to end its 10-year outsourcing contract with Capita, bringing services back in-house by 2026.
Most privatised frontline services - including highways and planning - will return under direct control of the council next year.
However, Barnet will extend the contract for services that are harder to bring back straight away such as IT and customer services until March 2026 to avoid redundancies and save £254,000.
Council leader Barry Rawlings said: 'This is the first major step we have taken to bring privatised services back in-house and shows our commitment to providing value-for-money for all our residents.
'Most of the services outsourced by the previous administration will be back under direct council control by next year.
'The decision to run services in-house will save Barnet's council taxpayers money and return 370 staff to direct employment by the council.
'The remaining Capita contract, CSG, will close by 2026, before the end of our administration's first term.'
The council first awarded Capita the 10-year contract back in 2013, covering services such as HR, finance, IT, estates, customer services, and the revenues and benefits service.
Barnet then formed the Regional Enterprise partnership with Capita to run services including highways, planning, regeneration and development, and environmental health.
A Capita spokesperson said: 'In the last nine years, our teams have successfully delivered a range of key services in Barnet.
'The extension on other services will see us build on our track record of delivery and save Barnet LBC £254,000, as well as preventing £2.6m in additional costs per year.'
