The airport organization told Taipei Times that they have sent notices and fined the airlines for late payment, but has not received any responses yet.
The organization says collecting payment may be difficult as both airlines are foreign carriers and their local management has quit.
They are also not considering pursuing legal actions against the airlines as they may end up paying more than what their owed.
Both airlines would need to pay off the fees should they resume their services.
Palau Airways was launched early last year serving flights between Palau and Taiwan.