Ulster Bank will begin deactivating remaining customer credit cards from today, as part of the process of winding down its operations here.
The development will mean any recurring transactions that are still being paid using an Ulster Bank credit card will be cancelled and go unpaid.
As a result, the bank says customers in such a situation will need to contact the relevant company to amend the instruction to another card.
It comes six months after the lender warned customers their cards would begin to become inactive on or soon after March 22.
The bank says customers with a remaining balance should continue to make monthly repayments in line with the terms and conditions of their card agreement.
It also says customers should clear their balance as soon as they can.
This can be done by applying for a balance transfer with a new credit card provider.
Alternatively, customers can use savings or apply for a personal loan with a new provider, the bank says in a message on its website.
A failure to make the required payment on a deactivated credit card account with an outstanding balance will put it into arrears, the bank has warned.
This could impact the customer's credit rating, making it more difficult to borrow money from other lenders in the future.
The bank, which announced it was leaving the Republic of Ireland market two years ago, says anyone who needs additional support can contact its card team on 0818-210261 or through its online customer support hub at https://www.ulsterbank.ie/help-and-support/support-hub/credit-cards.html .
Those wishing to close their credit card accounts can also do so through the phone line or online hub.
Ulster Bank has said its remaining 63 branches will cease carrying out transactions for customers on 31 March.
All the branches will then close on 21 April.
The bank began freezing and closing accounts of customers whose notice had expired last November.