The long-established Central Avenue facility had been due to close in the summer along with all its other sister offices in Annandale and Eskdale.
But following a growing public and political backlash to the largely publicly-owned bank’s plan to close 62 of their Scottish branches, 10 have been given, at least, a temporary reprieve.
While Gretna receives a second chance, other branches at Annan, Lockerbie and Langholm are still due to close as planned.
Executives are understood to be looking to see if the border branch picks up extra counter business when the other local banks close their doors.
RBS confirmed that in the coming months they will monitor the level of transactions and new income.
They also revealed that where no buyer comes forward to purchase closed branch buildings, they would consider working with development trusts and local communities to transfer ownership for public use.
This week south west politicians condemned RBS for not going far enough to maintain their branch network.
Local Conservative MP and Scottish Secretary David Mundell welcomed the Gretna reprieve but pointed out it would be ‘worthless’ if the branch shut at Christmas.
He said: “This is merely a stay of execution for the branch and it is hugely disappointing for RBS customers in Lockerbie, Annan and Langholm who wish to have a branch on their doorstep.”
Mr Mundell encouraged Gretna RBS customers to use the branch to help secure its long-term viability.
He added: “We should never have been faced with these closures in the first place, but now RBS have an opportunity to work with local communities to secure the long-term future of the Gretna branch.”
South of Scotland Labour MSP Colin Smyth slammed what he described as the UK Government’s failure to intervene to halt the taxpayer-rescued bank’s ‘entirely preventable branch closures.’
Meanwhile, while welcoming the Gretna decision, SNP South of Scotland MSP Joan McAlpine called on Mr Mundell, as Secretary of State, to further lobby the bank “to stop these closures completely.”