It's a two-second action which could prevent another lockdown, but most people aren't doing it.
Photo: RNZ
Use of the Covid-19 tracer app has dropped dramatically over the summer - the number of daily scans on the app is down to a fifth of its peak use.
It's barely half a million scans across the country each day, and only 22 percent of people are using the new Bluetooth tracing feature.
Hospitality New Zealand's chief executive officer Julie White told Morning Report New Zealanders need to make sure that they continue to use the tracer app.
"This wicked new variant, which is highly contagious, the risk is really high that we could end up in another lockdown if it arrives in the community," she said.
White said a lot of businesses are doing the right thing and have codes easily accessible to customers.
"We've done a really good job of keeping Covid at bay but the risk is still imminent."
Some hospitality businesses are reminding customers to sign in, but people are reacting to this in different ways, White said.
The responsibility to ensure people sign in should not be on one sector, she said.
"I think it comes down to that false sense of security that we've beaten Covid, there's a little bit of complacency around using the tracer app so we're quite concerned as well."