The Consumers Association of Ireland has criticised Bank of Ireland for introducing new fees and charges.
From February, current account holders will have to have at least €1,000 going into their account every month or make at least nine payments every three months.
If they fail to do this they will face a charge of 28 cent charge for each transaction.
Around a million Bank of Ireland customers are expected to be affected.
CEO of the Consumers Association of Ireland, Dermot Jewell, said: "The reality is that quite a lot of people, because of the challenges in the Budget, will be brought into the tax net and they will have reduced levels of credit.
"Bank of Ireland have done this knowing that it is going to affect their customers. There is a double affect here: they are going to be paying bank charges and they are going to have less money coming in."