The closure will enable the completion of work on the brand-new Northern line tunnel and passenger concourse at Bank Tube station. It comes as part of the Bank Station Capacity Upgrade, which aims to increase capacity at Monument and Bank stations by 40 per cent.
TfL said the closure would also mean a reduced service on the line between Camden Town and Moorgate, though services will be ramped up on the Charing Cross branch of line during peak periods.
An additional bus route, the 733, will also run from Oval to Finsbury Square every 7 to 8 minutes to help mitigate the disruption.
However, TfL warn that other tube stations - particularly those on the Charing Cross branch - will likely become busier during the closure.
As such, they urge commuters to travel outside of peak hours, between 08.45am and 4.30pm and after 6.45pm on weekdays.
Andy Lord, Managing Director of London Underground, said: “The 17-week closure of the Bank branch of the Northern line is now two days away, and we’re urging customers to check their journeys before they travel by using Journey Planner or the TfL Go app.
“We’re asking customers to consider taking journeys at a different time or via a different route, using alternate Tube lines or rail, bus, walking or cycling options.
“We’re introducing an increased service on the Charing Cross branch and a new bus route into the City, which will help people to get around during the closure.”
Bank, together with interlinked Monument station, was one of the busiest on London’s transport network before the pandemic, seeing up to 120 million passengers in a normal year.