If you're one of the many customers likely to be affected, what can you do?
The group, which remains 72 per cent taxpayer-owned after being rescued by the government during the 2008-9 financial crisis, said 62 locations in Scotland are set to be closed, as well as 197 NatWest branches in England and Wales. In England and Wales the number of NatWest branches will fall to 655.
The redundancy programme will lead to about 680 redundancies and the RBS branch network is aiming to manage this process on a voluntary basis.
Today's reductions follow 360 redundancies earlier this year and bring the total number of branch closures announced since March to more than 400.
"Closing a branch is a decision we take very seriously".
Royal Bank of Scotland will close 259 branches and cut 680 jobs to reduce costs and encourage customers to use online and mobile services, Reuters reports.More news: SCO Summit: Sushma Swaraj attends dinner hosted by Russian PM
NatWest spokesperson Kate Visser said: "Since 2012 we have seen the way in which people use NatWest Gainsborough branch change dramatically, with now 86 per cent of customers already banking in other ways locally".
The company is blaming the closures on the fact that more people are choosing to do their banking online.
The union's national officer Rob MacGregor also said the move could effectively signal the end of banking in branches.
"I call on the Royal Bank of Scotland engage immediately with their island customers and businesses to find a way to ensure that the island isn't deprived of essential financial services".
"This announcement will forever change the face of banking in this country resulting in over a thousand staff losing their jobs and hundreds of high streets without any banking facilities". As part of this, our new community banker provides customers with personal assistance and support to access our non-cash services, as well as help with achieving their financial plans and goals - replicating numerous services available in our branches.
"Why is the Government signing off this alarming branch closure programme?"