Thurles Credit Union and its counterpart in Edenderry, County Offaly are providing Visa debit cards and current accounts.
Another four credit unions are also said to be piloting debit cards.
Recent reports also suggested that eleven of the largest credit unions in the country are close to launching MasterCard debit cards.
Experts says banks will view the moves as a direct threat to their strength of providing day-to-day current accounts and payment cards.
