Ticketless parking fines have exploded in use in NSW as councils are urged to stop slyly notifying drivers well after offences occur.
Some 822,000 ticketless parking fines were issued in the year to June, up 49 per cent on the prior year.
That's despite most councils being halted from joining the system introduced in 2020.
Under the system, councils can issue fines without first giving drivers an immediate notification at the time the parking infringement is identified.
"The immediate notification is so important so that you can take a photo at the time and collate your evidence," Finance Minister Courtney Houssos told reporters on Wednesday.
"You can't do that if you receive a letter in the post a few weeks later."
Most councils had agreed to revert to paper tickets or introduce a notification system (usually a paper card) but there were holdouts, Ms Houssos said.
That has left the government considering setting statewide rules to establish a "common-sense, fairer" system for digital fines.
But a union said reducing the need for a ticket to be left on a windshield had spared parking inspectors the violence too often perpetrated by aggrieved drivers.
"We've seen some really violent attacks, including broken bones, femurs, arms, where people have gone into a violent rage as the parking officer writes out the ticket," United Services Union general secretary Graeme Kelly told ABC Radio.
He questioned whether the noted rise in infringements indicated rangers no longer had to let motorists off to avoid violent confrontations.
"I think you've noticed an uptick in tickets because they feel more confident now," Mr Kelly said.
City of Sydney, which issues 5200 parking fines a week, almost all paperless, said it had recorded a 33 per cent reduction in aggression and abuse directed at staff since switching to the digital system.
It was reviewing the government's request but endorsed the status quo.
"The system provides motorists with more information about the infringement, as well as follow-up actions available," a spokesman told AAP.
"It ensures the motorists are notified even if tickets go missing or are damaged by weather."
Ms Houssos said she had zero time for violence against rangers.
But there was a middle ground that could keep rangers safe and re-establish fairness as a core element of the system, she suggested.
Since concerns were highlighted in March, 30 councils have stated they have or will leave instant, on-the-spot notifications for drivers, such as a paper card.
The ticketless fine system began as a trial in May 2020, before being expanded to more councils in December 2020.
Motorists can still challenge fines through Revenue NSW
NSW PARKING FINES IN 2023/24:
* Ticketless parking fines: 822,310 (up 49 per cent on 2022/23), raising $158.0 million (up 54 per cent)
* Traditional parking fines - 558,634 (down 22 per cent), raising $95.6 million (down 14 per cent)
* Total - 1.38 million fines, raising $253.6 million
