As of midnight on Monday, gatherings in Australia will be restricted to two people in a further attempt to contain the coronavirus pandemic.

The two-person limit does not apply to people within your own household. But gatherings with other friends or family, outdoor or indoor, will need to comply with the new restriction.

What happens if you don't comply will depend on which state you are in.

Here's what we know about the penalties you could face, depending on where you are:

New South Wales

Premier Gladys Berejiklian said authorities would be cracking down on those breaking the two-person rule.

Despite it not coming into effect until Monday night, Ms Berejiklian said she wanted people to start practising it during the day.

"I am pleased to say NSW will be acting quickly to enforce those provisions that were discussed last night," she said.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 2 minutes 19 seconds 2 m 19 s Gladys Berejiklian announces NSW will enforce social limits.

NSW Police Commissioner Mick Fuller confirmed police would be enforcing the new rule.

"We know there are some new laws that will come into place tonight (Monday) in relation to two people being out together. That is sensible," he said.

"We don't want to have to enforce these laws. We want to work with you. We will just ask the public to read up on the new laws and be sure the police will be out there."

Victoria

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 1 minute 36 seconds 1 m 36 s Victorian Premier Daniel Andrews has moved the state to stage-three coronavirus restrictions.

Premier Daniel Andrews said Victoria had moved to stage three restrictions, which come into effect from midnight.

That involves an on-the-spot fine of more than $1,600 if you breach the two-person rule.

"If you are outside, or in your backyard, gathering in more than two people, if you are having friends over for dinner or friends over for drinks that are not members of your household, then you are breaking the law," Mr Andrews said.

Tasmania

The Tasmanian Government said it would be an offence to congregate in larger groups.

Premier Peter Gutwein has foreshadowed on the spot fines for anyone not complying.

"You will be able to be arrested. You will be charged and summonsed," he said.

"These are tough measures, but they're done with Tasmania's health, wellbeing and safety as our first priority."

Northern Territory

NT Chief Minister Michael Gunner said police would not be enforcing the two-person rule, but urged people to do the right thing.

"My priority for the police is to secure our borders, protect our remote communities, and make sure everyone who is meant to be in quarantine is doing the right thing," he said.

"If it's something that needs to be enforced down the track, we'll do that. Police are currently enforcing a limit on groups of 10."

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South Australia

South Australia Police Commissioner Grant Stevens said the national directive would not be enforced in the state.

"The advice coming from the National Cabinet is that gatherings of two or more should be discouraged and we'd certainly be encouraging people to take that as strong advice, to limit the number of people that they're engaging with other than family members," he said.

"But when it comes to enforcement we'll be looking at that 10 or more rule."

South Australia has banned gatherings of more than 10 people - not including family members.

Individuals who don't comply with that rule can be fined $1,000, while businesses face a $5,000 fine.

ACT

ACT Chief Minister Andrew Barr said the first phase of enforcing new rules would be about education and warnings, but the second phase would include the capacity for police to issue fines.

"In the first instance we do want to educate and warn people, so it won't be moving immediately to issuing fines, but if there is flagrant abuse of this, people should expect to be fined," he said.

Queensland

In Queensland, on-the-spot fines of $1,330 for individuals and $6,670 for corporations can be issued by police for breaching new public health directions.

Those caught ignoring quarantine directions could face penalties of up to $13,345 or $66,670 for corporations.

Western Australia

On Sunday, the State Government said it would be introducing urgent legislation into Parliament for on-the-spot fines to be issued.

The penalties will include $1,000 fines for individuals and $5,000 fines for businesses who disobey the rules.