South Australia's police commissioner has urged all people to use QR codes when checking into businesses and other venues to aid the fight against COVID-19.

South Australians have been urged not to skip checking in at businesses and other venues with QR codes, with the state's police commissioner warning against complacency in the fight against COVID-19.

Grant Stevens said that while South Australia was doing exceptionally well, the virus had not gone away.

"In South Australia, things are almost normal and that carries some risk and that makes people less vigilant," Mr Stevens told radio FiveAA on Wednesday.

He said while police had received considerable feedback suggesting people were "streaming" into venues without checking in, the issue was not as simple as it seemed.

The commissioner said scanning the code was not actually a condition of entry.

The only requirement is for people to check in at some stage while in a shop or other venue. It can be done at any time they are there.

"But there is a need to really reinforce that requirement and we need to reinforce with businesses that they are obligated to make sure people check in," Mr Stevens said.

Premier Steven Marshall said he believed there had been widespread acceptance of the technology which provided invaluable information for contact tracing.

"We're really looking for a stamp of where people have been," he said.

"What we're trying to do is piece together where people have been to get on top of this virus as soon as there is an outbreak."

Mr Stevens also moved to reassure the public on Wednesday that QR codes were not here to stay with no plans to keep the system in place once the pandemic was over.

He said that threshold would come when the state's public health officials no longer believed COVID-19 was a threat to the broader community and particularly the vulnerable.

"When we know that we've hit that threshold we will remove these things. They are not here forever," the commissioner said.

"They are here for the foreseeable future until we know we've got a handle on COVID-19."

On Thursday, South Australia's transition committee will meet to consider possible relaxing of local restrictions ahead of Australia Day.

Discussions are expected to include increasing the size of private gatherings, currently capped at 50 for homes and 200 for other venues.

The committee is not expected to make changes to SA's current border restrictions with NSW, with people coming from Greater Sydney, the Central Coast and Wollongong not allowed into SA unless they are a returning local resident, have an exemption or are an essential worker.

SA authorities want to wait for 14 days of no community transmission before easing the border rules, which would suggest a timeframe towards the end of January, assuming there were no more cases.

South Australia reported one new COVID-19 case on Wednesday, in a man in his 30s who recently returned from overseas.

He is one of six active infections in the state, all in hotel quarantine.

There have still been no reported positive cases among tennis players and their support staff in Adelaide for an exhibition tournament later this month.