Returning overseas travellers, who are forced into hotel quarantine in Sydney, will have to pay for accommodation and meals from next Saturday.
The state government will impose a charge of $3000 for an adult, $1000 for each additional adult in a group and $500 per child. Children under three will be free.
Hardship provisions will apply and the charges will not apply if tickets were purchased before today's announcement.
Premier Gladys Berejiklian announced the new policy at a coronavirus update on Sunday.
Ms Berejiklian said people had had in excess of three to four months to consider their options.
The government had heard of some people travelling overseas and returning more than once during the hotel isolation period, she said.
"I know for some people overseas this decision might be regarded as tough but we have to put the health of our residents in NSW first," she said.
Ms Berejiklian said travellers would still be only paying a portion of the full cost involved in the program, in which security is a costly factor.
Ms Berejiklian and NSW Chief Health Officer Kerry Chant also requested anyone who had visited Crossroads Hotel at Casula, near Liverpool, anytime from July 3-10 undergo a test and self-isolate for 14 days.
The hotel was identified on Friday as a source of community transmissions, and a staff member tested positive on Saturday night.
Previously, people were only asked to be tested and self isolate if they were at the hotel on July 3.
There have been five new coronavirus cases in NSW in the last 24 hour reporting period.
No further cases have so far come resulted from the man who towed his caravan from Victoria to a Sutherland Shire caravan park.
Dr Chant said two of the new cases were returned travellers and three were associated with the case from the Blue Mountains, linked to the Crossroads Hotel.
The case of the hotel staff member will be included in tomorrow's figures.
Ms Berejiklian said NSW was at "a critical point" in the fight against coronavirus.
"We have the chance in the next three weeks to really clamp down on community transmissions or unfortunately we will go down the path of what Victoria is going through," she said.
Ms Berejiklian said people should not be surprised if the government took more steps to limit gatherings.
"If compliance is not working and businesses have hundreds of people, if we see it is not maintained, we will need to take action," she said.
