Lloyds Banking Group has announced that its Ystradgynlais branch will close this year.
The closure will come into effect on September 19 2023, with customers of the bank set to receive a letter to notify them of this closure.
In its most recent branch closure review, Lloyds said the decision was made because customers are using it "less often". It also added that the majority of customers are also using alternative ways to bank.
Lloyds reported that 93 of its customers used the branch on Commercial Street regularly in 12 months to October 2022.
Branch transactions at the Ystradgynlais branch fell more than 67 per cent between 2017 and 2022.
The nearest Lloyds branches following the closure would be in Ponterdawe (5.7 miles away) and Neath (10.1 miles away).
For a period of time after the branch closes there are plans for a Community Banker to visit the area.
James Evans, MS for Brecon and Radnorshire, said it was "disappointing news" and "a real blow" to the town.
"Unfortunately, this is part of a wider trend, where we have seen towns lose all their banking services – from Hay-on-Wye in the east to Ystradgynlais in the west," said Mr Evans.
“I have asked to meet officials from Lloyds Bank to discuss this matter urgently. I want all customers to be supported, and to ensure that suitable arrangements are put in place for those unable to travel to the Pontardawe branch.
“If anyone has concerns about this closure, please email my office or call in at our surgery in the Library on the second Thursday morning of each month."
Jane Dodds, MS for Mid and West Wales said: “This decision will see yet another Powys town left without a bank. This time it isn’t even one of our smaller villages but the second largest town in the entire county with a population of over 8,000."
She added that the trend "cannot continue" and said that banks need to recognise they have "a duty" to provide in-person services.
"Not everyone uses online banking, particularly in rural areas like Powys," she said.
“I will be requesting a meeting with Lloyds Bank urgently to make my views known and raise the concerns of my constituents."
Brecon and Radnorshire Parliamentary Candidate David Chadwick added: “This is a disappointing and short-sighted decision by Lloyds that they should urgently reconsider.
“Just last month the bank reported it had almost doubled its profits to £1.8 billion. Banks like Lloyds should show some loyalty to customers in rural areas who contribute to their operations.
"All these banks have diversity and inclusion policies, yet none seem to consider the elderly or digitally excluded in them.
“What is even more frustrating is both of Powys’ Conservative MPs stood against a proposed piece of legislation last December that would have protected access to cash in rural areas. Once again our local MP has failed to stand up for her constituents and we are all feeling the impact."
A Lloyds Bank spokesperson told the Brecon & Radnor Express: “Visits to our Ystradgynlais branch have fallen over recent years, as many customers now choose to bank digitally.
"When the branch closes in September, customers can use the local Post Office for everyday banking which is a short walk away, access cash at the free-to-use ATMs less than a mile away, alongside other ways to bank such as over the phone and online."