The transport watchdog has received over 290 complaints about taxis not accepting card payments, or not having a card machine.
The complaints - released under the Freedom of Information Act to the Today FM newsroom - were made over the past seven months.
Since last September, every taxi in Ireland must accept credit and debit card payments, as well as cash.
The transport watchdog has issued 79 fines following roadside checks for ‘cashless payment device’ offences.
Jim Waldron, from the National Private Hire and Taxi Association, says it's taking time for drivers to adjust to the cashless payment system:
"I'm not surprised," he said.
"I think it's taken a little bit of time for transition to happen for drivers to adapt to and to equip themselves with cash as payment systems.
"They should have been doing this since last September, but I think they're all getting in line now."
Jim Waldron also believes it is more difficult for older taxi drivers, and said, "they wouldn't be very well versed on the use of electronic equipment and that type of thing.
"So I think it's taking them more time to transition."