The ACT will accept 150 returned international travellers every 16 to 18 days, in a bid to help more Australians stranded overseas to get home.
National Cabinet will also consider allowing business travellers to quarantine in corporate camps, as part of a "risk stratification" model for international arrivals.
Prime Minister Scott Morrison announced the caps on international travellers would ease slightly to allow more Australians to get home.
Western Australia will allow an extra 140 travellers in, while Queensland will allow another 150 people in.
Adelaide will accept 100 arrivals every 14 to 16 days, while the ACT would support 150 returning Australians every 16 to 18 days. The ACT arrangement is still being finalised.
Mr Morrison said he wants to get the 26,000 Australians stuck overseas home for Christmas.
Nearly 4600 have arrived home since the quarantine caps were eased, including around 1300 of the 4000 people registered as vulnerable.
Australian Human Rights Commission president Rosalind Croucher told Senate estimates on Thursday the cap may breach Australia's international obligations.
The commission has received 125 complaints linked to the travel issues.
National Cabinet would also look further to when Australia could start opening its borders to more travellers.
Mr Morrison said states and territories had agreed to trial alternate quarantine arrangements, off the back of former senior public servant Jane Halton's nationwide review into the hotel quarantine system.
More than 130,000 travellers have been through hotel quarantine between March 28 and August 28 -96,000 international and 34,000 domestic travellers. There have been 90 complaints to the Human Rights Commission about hotel quarantine, including about lack of access to fresh air, as well as the quality and size of the accommodation.
The review found existing models of quarantine were unlikely to be able to expand significantly above current capacity and new risk-based approach was needed.
"Pressure to increase travel for both personal and business needs is increasing. The need to import skilled labour including for agricultural and critical maintenance tasks has been highlighted as an increasing priority," Ms Halton wrote.
"The current system has a high cost, requires highly specialised skills and impacts guests financially, emotionally and physically.
"While the system has largely performed well and there are ways to improve the operation of the existing system through the adoption of best practice, the need to increase the flow of travellers has been brought to the attention of the review."
Ms Halton said it was likely some form of quarantine would be needed for some time.
"It is likely that an effective vaccine for COVID-19 will not be available for wide adoption in the near future and effective treatments are yet to be identified," she said.
"The sheer scale of vaccinating vulnerable people globally will mean an effective first line of defence will need to be maintained."
Mr Morrison said National Cabinet would examine other ways international travellers could isolate safely.
"So whether it is quarantining in on-farm, in-camp at a mining camp, on campus, any of these options we will be looking at and working together with states and territories to both identify and trial some of these options so when we are in a position to make further decisions on arrivals to Australia, then they will be well worked through and we can have a great degree of confidence about their implementation," Mr Morrison said.
Mr Morrison also said there was strong interest from large corporate firms to set up their own quarantine facilities under strict guidelines and overseen by state health authorities.
"The more options we can identify, the more capacity it frees up, the more we can move back to more normal arrangements," Mr Morrison said.
"There's no undue haste, there is undue risk and we've agreed before we make any of those decisions, we want to know what the options are, whether they work and whether they are safe.
"You don't want to build that aeroplane in the sky, you want to build it before it takes off."
Mr Morrison also said seven of eight states and territories also agreed to the Coalition's reopening framework, which will aim to have Australia's internal borders open by Christmas.
Western Australia remains the only jurisdiction that has not agreed to the framework.