Since 2015 there have been 2,868 branches closed or scheduled to close by the end of 2018, according to analysis by consumer watchdog Which?.
Natwest has closed the most branches, with 638 having shut, or scheduled to close by the end of 2018.
This is followed by HSBC with 440 closures, Lloyds with 366 and RBS with 350.
Closures have been accelerating since 2016, the data showed.
This year 670 branches have closed or been scheduled for closure, meaning there may be more in 2018 than 2017.
Scotland hardest hit
By region, Scotland has been worst hit, with 368 branches having shut since 2015, or scheduled to close by the end of 2018.
This is followed by the South East with 361 closures, the North West with 353 and South West with 327.
Bank branch closures are also accelerating at a time when the free-to-use ATM network is under threat from changes to the way it is funded, according to Which?.
This combination of branch and machine closures could leave the 2.7 million people almost entirely reliant on cash struggling to conveniently access their preferred payment method, the campaign group said.
The branch closures reflect a change in the way customers are banking, as customers choose to move more transactions away from branches and towards digital channels.
Which? money expert, Gareth Shaw, said: “While the decision is clearly a commercial one for a bank to take, it is also crucial that banks do recognise the needs of their customers and the communities they serve, before simply shutting their doors – and their customers out.”
A spokesman for NatWest said: “More and more of our customers are choosing to do their everyday banking online or on mobile.
“Since 2014 the number of customers using our branches across the UK has fallen by 40% and mobile transactions have increased by 73% over the same period.
“Over 5.75 million customers now use our mobile banking app and one in five only bank with us digitally.
“We’re providing our customers with more ways to bank than ever before – they can choose from a range of digital, to face-to-face options.
“As customers continue to change the way they bank with us, we must change the way we serve them, so we are investing in our branches and re-shaping our network, replacing traditional bricks and mortar branches with alternative ways to bank, including; Community Bankers, Mobile Branches, and Post Offices, so that we can reach even more customers.”