The Isle of Man bank is to close one of its village sub-branches in the west of the island on 10 August.
A bank spokesman said the growth of telephone and internet banking meant few customers were using the Kirk Michael service, which opened in 1953.
He said the bank, owned by the Royal Bank of Scotland Group, will not be making any redundancies.
Managing Director Bill Shimmins said the decision to close the village service has not been taken lightly.
He added: "This service in the village of Kirk Michael has experienced reduced usage as customers choose alternative ways of banking, such as 24 hour online or telephone services.
"Customers can continue to receive a full branch banking service at Peel and Ramsey."