Irish Rail has collected more than €1.2m from fare dodgers in the last 18 months.
Rail bosses say that since January 2018, 19,908 people were caught out on board without a valid ticket for their journey.
20% were fined for not using their Leap Card to tag on prior to travel, while 13% were adults who were penalised for travelling on a child or student tickets
Irish Rail spokesperson Barry Kenny says some fines were issued to people without any ticket at all
There have been calls that the revenue collected through these fines should be put towards paying for increased security on services.
Mr Kenny says that would make no sense.
He said: "If you were actually funding someting as important as security measures exclusively from a pot of money that ultimately, in a perfect world, you'd like to get to zero - then that's not actually the right way to do it.
"We are increasing the funding for security measures, for security personel, for CCTV, for text alert for all those systems separate to that and separate to any variation that there might be in the pot of money that comes in for fare evasion."