The Commonwealth Bank branch in Kingston ACT will close on June 30 but the ATM will remain.
The bank advised customers of its decision recently and confirmed details with Fairfax Media.
It's understood the BSB number will remain and staff will be redeployed.
Customers are being encouraged to make transactions at the neighbouring Australia Post office.
"Commonwealth Bank regularly reviews its branch footprint, including opening new branches, installing new technology, refurbishing, relocating and in some instances closing branches," a spokesman said.
"The decision to close this branch was not an easy one and we understand some members of the community may be disappointed.
"We have identified that fewer customers use this branch following a steady decline in transactions as they choose to use other banking channels like online and mobile.
"Over the last five years we've seen a 40 per cent decline in the number of transactions at our Kingston branch."
Commonwealth Bank data shows branch deposits and withdrawals across Australia have fallen from $130 million in 2003 to $56 million while internet transactions have climbed from $40 million to $684 million.
The Commonwealth Bank branches closest to Kingston are at Manuka and Fyshwick.
There were mixed reactions to the Kingston branch closure on The Canberra Times Facebook post.
One reader said it was "annoying" because Kingston was more convenient than Manuka for depositing an occasional cheque.
Another said the Manuka branch was above Coles, making it more difficult for frail and disabled people to access.
ANZ closed its Fyshwick branch in March.
