The FAI have confirmed that Waterford have been denied entry to next season's Europa League.
This week, St Patrick's Athletic wrote to the FAI to question Waterford's eligibility for a UEFA license as club's trading company is less than three years old.
In order to compete in European competition, a club must be at least three years old.
Waterford FC's management company was only formed in late 2016.
Waterford qualified for the Europa League by finishing fourth in last season's SSE Airtricity Premier Division but the FAI say UEFA have denied their exemption request.
The FAI have not yet confirmed that St Pat's will take Waterford's place.