The Eric Parry designed 10-storey building will provide 260,000 sq ft of offices with ground floor shops within a new building known as One Liverpool Street.
The existing site is split into two: one part straddling the Crossrail Station and the other part requiring demolition of a 1980s office building.
Demolition of the current building at 1-14 Liverpool Street will now get underway with the site being cleared by the start of next summer.
Construction of the new building is expected to be complete, including fit-out, by the start of 2023.
The design team includes Mott MacDonald as a structural consultant and AECOM delivering building services.
WT Partnership is the project manager, with Gardiner & Theobald acting as cost consultant.