Almost 500 jobs are to go through the closure of 158 bank branches - the majority of them under the NatWest brand.
The growth of digital popularity has been cited by the industry as the core reason for the erosion of branch operations since the financial crisis.
A report by Which? in December pointed to over 1,000 closures over the past two years - with HSBC saying in January it would shut 62 more in 2017 to create a "sustainable network".
Loss-making RBS, still majority-owned by the taxpayer after its bailout in 2008 and still mired by legacy costs, said 30 RBS and 128 NatWest branches would be affected by the new closures, alongside 770 staff.
But it added that 300 of those people would be kept on to fill new support roles - to aid people in rural communities and help boost customers' digital skills.
But the bank said: "We have seen a dramatic shift in the way our customers are choosing to bank, with more using mobile and online over traditional branch counters.
"Simple transactions undertaken in branch at NatWest and Royal Bank of Scotland have fallen by 43% since 2010, while online and mobile transactions have increased by more than 400%."
A spokesman added: "We interact with our customers over 20 times more through digital channels than physical ones.
"We have 4.2 million personal mobile users, up by over two million since 2014. As customers change the way they bank with us, we must change the way we serve them.
"The role of the branch is fast moving to a centre for advice, away from basic transactions.
"While the branch will still be a core part of our offering to customers, inevitably some branches will have to close."
The group will have 151 RBS and 856 NatWest branches left after the closures are implemented.