Victoria will further ease COVID-19 restrictions for businesses and venues on May 28 as the state finally moves to a single QR code check-in service.

Five Victorians are isolating after being identified as exposure site contacts in the NSW COVID-19 outbreak.

Three have tested negative and the other two are awaiting their results, the state health department says.

More than 55,000 SMS messages had been sent to Victorians returning from NSW since April 30, telling them to check whether they had visited exposure sites.

Anyone who visited the sites, able to be viewed online at nsw.gov.au/covid-19, must isolate and get tested, as well as contact the Victorian health department.

The news comes as Victorians learned they will finally have a single QR code check-in, with the state also to further ease business and venue COVID-19 restrictions.

From May 28, anyone required to keep electronic attendance records must use the state government's QR code through the Service Victoria app.

Also on May 28, density requirements of one person per two square metres will be lifted for small-to-medium sized spaces.

Venues such as dining or band rooms and places of worship can have up to 200 people without any density limit, provided COVID-19 marshals are on site.

Density limits will remain for spaces above 400 square metres.

But the Victorian Chamber of Commerce and Industry, which has welcomed eased restrictions, wants them removed altogether.

It also says the QR code change is frustrating.

The state government remains worried about low check-in rates and it has called on any Victorian with a smart phone to download the Service Victoria app.

Victoria is behind other states such as NSW and South Australia which already use a single QR code.

The state government quoted a survey that showed only 41 per cent of people at hospitality venues check in every time, while nearly a quarter of venues were warned or served notices in a crack down between April 30 and May 2 because of poor record keeping.

Health Minister Martin Foley said all states had suffered a drop-off in QR code compliance.

He added events in Sydney this week showed outbreaks would keep happening.

"The simplest way to have higher levels of compliance is to have the simplest system," Foley said.

"Yes, by all means, lots of people promoted the idea of one simple app.

"Our system has worked more than adequately ... but we think this step in three weeks time will just make it simpler and easier to comply."

Victorian Chamber chief executive Paul Guerra said while the eased restrictions were a step in the right direction, the government had shifted the goalposts on the QR code system.

"Given today's developments, we should be taking all the restrictions off and opening up 'COVIDSafe' to full capacity, or 100 per cent," Mr Guerra said in a statement.

"If we are asking businesses to accept the inconvenience and disruption of swapping their record keeping systems, we need to let them operate at viable levels.

"Business needs certainty and this constant chopping and changing is making it difficult to keep up ... this process has been confusing and disorganised."

Victoria had no new hotel quarantine cases on Friday and the streak of no local infections has reached 70 days.

A record 9158 vaccinations were injected at state-commissioned services.