All stations on the line between Chingford and Liverpool Street will be upgraded when it becomes part of the Overground network in 2015, but the fleet of trains will not be replaced for three years, it has emerged.
Transport for London (TfL) is set to takeover the line in May next year and has pledged to invest in station facilities, including new ticket machines.
The current fleet of trains will also be fully cleaned but will not be replaced until the summer of 2018, TfL has said.
The contract to run the Overground network is due to be put out to tender in November 2016.
Fares on the Chingford to Liverpool Street line will not increase immediately when TfL take over, but could rise following a planned review a few months later.