More than 28,000 drivers have been on the road with a provisional licence for up to 30 years.
Figures from the Road Safety Authority show 28,570 are on their third or subsequent learner permit, and haven't sat a driving test.
However, the number who've never sat a driving test could actually be higher, as the stats from 1994 to 2008 don't include testing data.
Editor of CompleteCar.ie, Shane O'Donoghue, says thousands of learner drivers have been taking advantage of the system loophole for many years:
"If your learner permit is due for renewal, you only need to show that you've applied for a driving test before you renew your permit."
Shane says people never actually have to go through with the appointment, and turn up for the test.
"There are serial renewers, that never have any intention of sitting the test, but just keep renewing their learner permit."