U.S. banking giant JPMorgan Chase has announced plans to build a new 3M SF office tower in Canary Wharf, creating what would be the UK’s largest office building.

JPMorgan confirmed plans to develop the new building on a plot called Riverside at the edge of the east London district.

Canary Wharf Group is the co-developer on the project, and the UK property company’s former CEO Sir George Iacobescu has been independently advising JPMorgan on the plans.

The building has been designed by Foster + Partners and will house 12,000 staff. JPMorgan employs 23,000 people in the UK, including 13,000 in London, 5,300 in Bournemouth, and 4,000 in Glasgow and Edinburgh.

The development will take six years once planning permission is received.

JPMorgan operates in London primarily from two buildings it owns: 25 Bank Street in Canary Wharf, for its commercial and investment bank, and 60 Victoria Embankment in the City, for asset and wealth management. It also leases space at One Cabot Square to accommodate its international consumer bank.

Once the Riverside development is complete, London-based employees will consolidate in the new building as well as the existing property at 60 Victoria Embankment, and the firm will consider its options for 25 Bank Street, JPMorgan said. That could lead to a building of about 1.1M SF coming to the market, and the space in Cabot Square is also only leased temporarily.

JPMorgan has owned the Riverside site since 2008 and almost sold it in 2014, only to halt the planned sale at the last minute.

The bank has been one of the most vocal of all businesses about its desire to get staff back to the office five days a week.

JPMorgan Chairman and CEO Jamie Dimon cited London's longstanding and continuing importance as a financial hub in a statement about the Canary Wharf office plans.

“The UK government’s priority of economic growth has been a critical factor in helping us make this decision,” Dimon said in a statement.

The decision is a boon for Canary Wharf, which had seen some of its biggest occupiers leave over the past three years, like HSBC and Clifford Chance. Others, like Barclays and Morgan Stanley, have opted to stay.

Canary Wharf Group, the biggest property owner in the area, said that 2025 has been its best year for leasing in more than a decade.

“It marks a defining moment for Canary Wharf and underlines its position as the destination of choice for the world’s most ambitious and innovative companies,” Canary Wharf Group CEO Shobi Khan said in a statement.