The idea was raised at the Dublin Lord Mayor's Forum in City Hall when Irish political and business leaders met to discuss the development of an economic corridor between Belfast and Dublin.
Speaking about Tourism Ireland CEO Niall Gibbons' suggestion of an "Ireland credit card for our 70 million diaspora", Lord Mayor Oisin Quinn said there was a "forest of ideas" at Friday's forum.
The credit card would mean holidaymakers travelling to Ireland could use the bank-backed card to pay for their accommodation, travel, food and shopping.
It is also hoped that those who use the card would receive discounts along the way.
The idea was warmly received at the forum, and many of the business leaders present were very interested.
A Lord Mayor's Forum was held in Belfast after the Dublin event and Mr Quinn and Belfast's Lord Mayor Mairtin O Muilleoir signed an agreement for a Belfast-Dublin economic corridor.
The memorandum of understanding between the two mayors states that the "future economic growth on the island of Ireland will occur in the eastern corridor of the island".
Mayor Quinn and Mayor O Muilleoir both committed to the "development of their cities and the economic corridor that links them", launching an initiative seeking ideas that would boost economic growth.