Teens as young as 14 are being slapped with on-the-spot $1000 fines they have no way of paying, prompting calls for frontline police to show leniency during the coronavirus pandemic.

Dozens of fines have been handed down to minors over the last two months in NSW and although police first issue warnings, some teens have received as many as three $1000 fines in the space of just weeks.

One 17-year-old boy from Woonona, who had already been fined twice by police, was issued his third public infringement notice and a $1000 fine on April 21 for not having a valid excuse to be outside.

The boy claimed he was "bored" and had "nothing else to do".

Another 15-year-old boy, also from Woonona, was fined and issued with his second public infringement notice in two weeks for failing to comply with social distancing rules.

The boy claimed he was outdoors "to see a friend".

A 16-year-old boy from Manly who couldn't provide a reason for being outside was issued a $1000 fine on April 11, while another 16-year-old girl from Gosford was fined on April 16 for catching a train without a reasonable excuse.

The state government has been urged to amend legislation that allows minors as young as 10 to be slapped with the fines.

Leading the calls for change is Greens MP David Shoebridge who says that the hefty fines would be "financially crippling" for teens who are forced to cough up excessive amounts.

"A $1000 fine to a 16-year-old would be crippling, 99 per cent of 16-year-olds don't have access to that kind of money," Mr Shoebridge told The Sunday Telegraph.

"The interesting thing about this legislation is that none of the usual protections apply that prohibit the police from issuing fines to minors.

"I believe people should not be fined in this way until after they have turned 18, what's potentially achievable for an adult, is financially crippling for a 16-year-old.

"This public health crisis shouldn't become a revenue raising exercise and it especially shouldn't be at the expense of teenagers."

Mr Shoebridge said that he believes police should practice more leniency and avoid fining teens where possible.

"My call to frontline police is to acknowledge that kids are kids and teenagers and teenagers, persuade them, issue cautions, I think they should do everything they can do avoid issuing fines to minors," he said.

" … we sought to amend the legislation, instead of a stand-alone thousand dollar fine we've tried to amend the penalties under the public health order so that the first offence carried a $220 fine, but we didn't have the numbers."