A government Minister says the company providing NCT tests is not fulfilling its contract to the state.
Over 425 thousand vehicles are currently overdue for the test, with the waiting list growing by 50 thousand in the past two months alone.
Junior Transport Minister Jack Chambers is advising people to apply to the priority waiting list if their NCT is overdue.
He says the waiting time should only be 12 days:
"We're absolutely focused on sorting this and the delays are completely unacceptable."
"Applus who provide this on behalf of the state aren't fulfilling the contract of a 12 day average waiting time."
In October, the company hired extra workers from the Asia and Europe in an effort to bolster staff numbers within the NCT system, however wait times for a test date are still a concern.