From 11.59pm tonight density limits of one person per two square metres will be in place for indoor entertainment and hospitality venues.

Indoor seated cinemas and theatres will be an exception where people are seated and masked.

In the biggest change to the COVID-19 testing system since the beginning of the pandemic, Victorians won't have to line up to get a PCR test and wait for their result to be diagnosed with COVID-19.

READ MORE: Victoria has 21,997 new cases, six deaths

Under new pandemic orders, people who test positive on a Rapid Antigen Test (RAT) will be considered probable cases and be subject to the same requirements as confirmed cases from a PCR test - they must isolate immediately for seven days and notify their contacts.

It will be mandatory to report the result of a positive RAT to the Department of Health through an online form or by phone in response to that state's urging Omicron outbreak.

Once a probable case has reported their positive RAT result, they will be asked questions about their symptoms and directly provided information about their next steps, how long they must isolate and how they can get care and advice - just as they would if they tested positive on a PCR test. Probable cases will be reported alongside confirmed cases in Victoria's daily numbers.

Victoria's acting chief health officer Ben Cowie said 95 per cent of people that have a positive RAT go on to have that result seconded by a PCR.

"This is the biggest change to our testing system since the start of the pandemic," Professor Cowie said.

Until RATs are in increased supply, Victorians who have symptoms, or asymptomatic household contacts required to use RATs, can still get a PCR test if they can't access any RATs.

A PCR test continues to be recommended for people who test positive on a RAT but don't have symptoms and who aren't contacts. Due to the increased accuracy of RATs in higher-risk groups, PCR tests will be discouraged for contacts or people with symptoms.

Those who record a positive RAT will receive the same support as PCR positives.

The online and phone reporting system will go live on January 7.

Victoria is in a new phase of the pandemic, Victorian Health Minister Martin Foley said.

"We think this is a sensible change, particularly in the face of the continued huge growth in transmission, particularly amongst young people," Minister Foley said.

"Of yesterday 's formal figures, 40 per cent of those cases were people in their 20s and every indication is it's overwhelmingly from hospitality and related environments

"These measures, we hope, will facilitate both the continued operation of the hospitality sector while at the same time encouraging greater activity outdoors.

"We will reiterate the very strong recommendations to businesses and their patrons when it comes to avoiding indoor dance floors and opting for seated service as a preferred method every time you can."

One in three Victorians are returning a positive test.

The strong recommendation to work from home and study from home for adult education if you can will remain in place until Australia Day.

More to come.

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