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, 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, said it is taking time for drivers to adjust to the cashless payment system.
Mr Waldron told Newstalk: "I'm not surprised, I think it is taking a little bit of time for the transition to happen and for drivers to adapt and equip themselves with cashless payment systems. They should have been doing it since last September but I think they're all getting in line now."