RBS is shutting 44 branches across the UK, blaming a 30% fall in in-store transactions over the last few years for its decision.
The bank - 81% owned by the taxpayer thanks to a 2008 bailout - says that 14 of the branches being axed are "the last banks in town", which are open for just a few hours a week and have very few customers.
The closures come despite RBS specifically pledging to stay open for business if it is the last bank in a town in a 2010 'customer charter' designed to rebuild public faith in the wake of the bailout.
Explaining the u-turn, a spokesman says: "Banking has changed significantly over the last few years as more and more of our customers are banking with us where and when it is convenient for them.
"We have to adapt to what our customers want, which is why we're investing in a range of other ways our customers can bank with us, including online and telephone banking, our mobile app, and in any one of the Post Office's 11,500 branches across the UK."
RBS says that there has been a 30% fall in the number of transactions carried out at its branches since 2010. The number of online and mobile transactions has now surpassed those taking place in branches and ATMs.
RBS recently ran a TV ad that billed a commuter train - the 7.01 from Reading to Paddington - as its 'busiest branch', with over 167,000 travellers using their mobiles to conduct transactions on their way into work.
However, the bank insists that it remains committed to its 2000-strong network, and that 93% of customers are still within 15 minutes of a branch.
Last week Clydesdale and Yorkshire Banks said they will close 28 branches after experiencing a similar drop off in usage. In November, Barclays confirmed plans to axe 1700 customer-facing jobs from its branch network in 2014, citing the rise of new customer channels, particularly mobile banking.
The change in customer behaviour is industry-wide. Figures release by the British Bankers Association this week show that Brits have now downloaded more than 12.4 million banking apps while the number of transactions made using them has nearly doubled in a year, hitting 18.6 million a week in 2013.