An NCT certificate is not a substitute for vetting a second hand car

[Brendan Burgess]

You can see the test stats for 2023 here

Test Statistics by NCT Centre

National Car Testing Service

www.ncts.ie

The pass rates ranged from 48% to 64% with a lot clustering around the average of 60% which is probably what you would expect.

It's likely that the variability is more due the variability of the cars being tested than the variability of the standards in the test centres.