Bank of Ireland is to close 15 of its branches in Northern Ireland following a strategic review of operations.
The decision is part of an overall plan to close 103 branches across the island of Ireland – leaving it with 182 remaining branches.
The bank will also move its UK headquarters from London to Belfast.
The bank currently has 28 branches in Northern Ireland, with the branches closing predominately self-service locations which do not offer a counter service, according to the bank.
The branches to close in Northern Ireland are: Ballymena, Banbridge, Belfast (Lisburn Road), Belfast (Ormeau Road), Belfast (University Road), Crossmaglen, Derry (Strand Road), Downpatrick, Dungannon, Keady, Limavady, Lisburn, Lisnakea, Portadown, Strabane.
In 2011, Bank of Ireland had 44 branches in Northern Ireland.
Bank of Ireland confirmed the closures would begin from June until "the end of 2021", with more specific dates for branches released "in due course".
Bank of Ireland said the change was part of a continuing trend of customers increasingly using digital services. It has also given a commitment that there will be at least one branch in every county.
"Technology is evolving, and customers are using branches less. COVID-19 has accelerated this changing behaviour, and over the past 12 months we’ve seen a seismic shift towards digital banking," they said.
“Digital banking is growing fast, while branch footfall is dropping sharply. We’ve now reached a tipping point between online and offline banking, and that’s why we’ve announced changes to our branch network. However, our agreement with the Post Office means we continue to protect local access to physical banking for those who want it.
“We know news like this can cause concern for some customers. We’re not making these changes immediately, giving us time to communicate fully with all our customers about every option available to them – online, in an alternative Bank of Ireland branch, or at a local post office.
“Bank of Ireland has been serving the community since 1825 and these changes mean we can continue to play a strong role in Northern Ireland for the years to come.”
Speaking on BBC's Good Morning Ulster, the Chief Executive of Bank of Ireland UK Ian McLaughlin, confirmed that the closures would affect around 120 employees, with the hope most could be redeployed within the company.
"Nothing is changing immediately for any of our customers," he said.
"We need to adapt and we need to change. We still will have a branch in every county. Access to cash and access to banking services will still exist."
Responding to the decision by Bank of Ireland, SDLP Economy Spokesperson Sinéad McLaughlin said the decision is "deeply concerning".
"Bank of Ireland’s review of its operations in Northern Ireland has caused anxiety for staff and personal and business customers," she said.
"I am deeply concerned at the implications of the decision to cut back its branch network which will have a devastating impact for staff, customers and also the high streets where these operate.
"I am calling on Bank of Ireland to urgently clarify its future plans for Northern Ireland, making clear how it will demonstrate its continued commitment and support for customers, employees and the communities where they operate."
Retail NI said the closure of the branches represented "a step too far" and could damage the high street.
Retail NI Chief Executive Glyn Roberts added: "The closure of these fifteen branches will have a negative impact on our local high streets with less footfall for nearby retailers when lockdown ends.
"I have also particular concerns of the impact on rural communities, with further reduced ATM provision and the ability to access cash.
"Our high streets face a huge task in recovering with so many businesses closing their doors which will lead to a growing problem of dereliction and shuttered shops."