A deal had been agreed in principle to enable a Crossrail station to be built.
The terminal at Woolwich in south-east London will be built without adding to the overall cost of the project.
Developer Berkeley Homes will build and pay for the basic box structure of the station, and construct its own development overhead.
Crossrail would link Maidenhead in Berkshire to Shenfield in Essex via Heathrow airport and tunnels under London.
The £10bn project was first proposed in 1989.
On Wednesday the project received a further boost when Sir Michael Lyons' report on local government suggested a way forward for the part-funding of the scheme.
Sir Michael suggested that supplementary rates imposed by local authorities could be used to raise cash to back long-term loans for transport links.
A 4p supplementary rate in London could finance a 10-year loan worth around £3.4bn, he said.
London mayor Ken Livingstone described the idea as "an extremely positive step towards securing funding for Crossrail".