In total, the decision will see the closure of 62 Royal Bank of Scotland branches and 197 NatWest branches.
An RBS spokesperson 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 million customers now use our mobile banking app and one in five only bank with us digitally."
The decision to close 259 branches is a blow to the customers who rely on them.
The full list of closures can be seen here.
The Rural Services Network says rural residents and businesses alrady face multiple barriers in terms of access to key services, including transport and broadband.
Rural communities contribute a great deal to the national economy but are facing threats to their future, says the network.
It has warned that rural areas will deteriorate further without action.
RBS says it is 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," said the spokesperson.
The bank says it is reshaping its network by replacing traditional bricks and mortar branches with alternative ways to bank.
These include through so-called "community bankers", mobile bank branches and post offices.
It said it was committed to ensuring our customers and communities remain able to continue accessing quality banking services.
"We are writing to customers of affected branches to highlight the alternative ways to bank in their area.
"Community bankers will get to know local communities, engage with local groups and provide training and education on issues such as fraud and scams protection in their local area."
The bank said it had "listened closely to feedback from local communities" and have extended the time between announcing our decision and the branch closure to six months.
It said this had been done in order to ensure our customers have time to consider the right banking options for them.
"Customers will also have a range of alternative ways to bank, including: online and mobile for simple transactions, telephony, and webchat for assisted help and the Post Office for face to face interactions."
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