The Abergavenny branch of Barclays is temporarily closed. A notice sign on the door of the Frogmore Street branch reads it is due to "circumstances beyond our control."
Over the past two days the bank has been closed to the public but it has reassured customers they are doing everything they can to "get things back up and running again."
There was no indication as to when the bank will reopen.
A spokesperson from Barclays said: "I can confirm Barclays Abergavenny is currently closed due to operational issues and an engineer is currently on site. Customers are able to use telephony, online banking and use the local post office for paying in and withdrawing cash. The closest alternative branch is Barclays Tredegar at 21-22 Castle Street, Tredegar. All customers have been notified by text message and we hope to have the branch re-opened asap."
There is also a Cash Point available at Tesco, 26 Frogmore Street, Abergavenny, NP7 5AH.