Arklow is among 30 centres nationwide are fully booked until at least November.
A shortage of staff and an increase in cars on the road are two of the the reasons for extensive backlogs, which are impacting centres across the country.
Drogheda has the longest waiting time, with a booking unavailable there until January 31st.
Meanwhile, as of this morning, there was an available slot tomorrow in Galway.
Other centres with no bookings available until next year include Dundalk, Naas, Skibbereen and Cavan.
While there were still available dates in August both in Westport and Ballina in County Mayo.
For those with expired NCT certs, Gardai say if a motorist can provide proof of test being booked then it will take this into consideration.
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