State and territory borders continue to tighten as more coronavirus cases emerge in NSW and Victoria.
The ACT has shut out NSW residents from the northern beaches, greater Sydney, the central coast and Wollongong, unless they have an exemption.
Those found entering without permission could be fined up to $8000.
ACT residents staying in NSW can still return home but need to notify the territory's health department of their plans via an online form and then quarantine for 14 days.
Tasmania has barred anyone directly linked to the latest Victorian virus cases, announcing on Saturday that its border was shut to anyone linked to one of nine sites where confirmed cases are known to have visited.
The locations rated "high risk" include a Thai restaurant in Melbourne's coastal suburb of Black Rock, which is linked to multiple positive cases.
"We will not hesitate to take further action should we need to," Tasmanian Health Minister Sarah Courtney said.
The island state's move follows its declaration of greater Sydney and the Wollongong area as medium-risk zones, requiring travellers to quarantine for 14 days on arrival, while those from Sydney's northern beaches are barred from entry.
Victoria recorded 10 new cases of community transmission on Saturday, all linked to the restaurant.
Two of the cases were reported on Friday, but counted the following day - a pair who ate at the restaurant on December 21 but were not contacted by Victorian authorities until 10 days later.
Victoria's border is now closed to all travellers from NSW after its deadline of 11.59pm on Friday for residents to come home without having to go into quarantine.
Testing sites in Melbourne and surrounds saw long queues and delays as thousands rushed to get tested.
NSW recorded seven new community cases on Saturday and Premier Gladys Berejiklian announced face masks would be mandatory for many indoor settings.
After previously opposing the idea, Ms Berejiklian said the change of heart balanced the health risk and security of citizens but allowed businesses to continue operating.
"What we want to do is make sure we're not in a situation where we are restricting people's ability to go about their business," she said on Saturday.
The change was commended by the Australian Medical Association, which has been calling for mandatory mask wearing since the start of the northern beaches outbreak.
Western Australia was the first to completely shut its border to NSW last year and has done the same for Victoria on Friday since new cases emerged there.
The Northern Territory has revised its public health orders and barred entry for all greater Sydney residents.
South Australia has re-established its hard border with NSW, along with a 100-kilometre buffer for border communities.
Queensland has confirmed one new case of COVID-19, but is yet to announce further border restrictions in response to outbreaks in NSW and Victoria.
The case confirmed on Saturday was acquired overseas and the state has maintained its streak of no community transmission.
Prime Minister Scott Morrison said he respects the decisions of state and territory leaders to shut their borders but understands why people have been left frustrated.
"As much as we would like there to be greater consistency across all of these things, we must respect (the states') jurisdictional authority," Mr Morrison told reporters on Friday.
The federal government had aimed for Australia to be fully open by Christmas, a plan dashed by the COVID-19 outbreak on Sydney's northern beaches.
People in Australia must stay at least 1.5 metres away from others. Check your jurisdiction's restrictions on gathering limits. If you are experiencing cold or flu symptoms, stay home and arrange a test by calling your doctor or contact the Coronavirus Health Information Hotline on 1800 020 080.
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