The station is the third busiest on the Tube network with more than 52 million passengers using it each year.
Transport for London says the planned upgrades will deliver faster interchanges, create more space for passengers, introduce step-free access to the Northern line and DLR platforms and create more direct routes including two new moving walkways.
Nick Brown, Managing Director of London Underground, said: “Improving Bank station is at the heart of our multi-billion pound investment programme to improve and expand the Tube.
“This critical and ambitious station upgrade will create a new southbound Northern line railway tunnel and platform to vastly reduce interchange times.
“A new station entrance on Cannon Street will also be constructed alongside a range of other major improvements to create more direct routes, improving accessibility for the millions of Tube customers who use Bank station each year.”
The station will remain open to customers throughout the work.