"Scanning is not natural, so the best way to do it is to offer something to the people," he said.
"For the simple act of scanning in, we'll give a 5 per cent discount off the bill - lunch and dinner," he said.
New Zealand reported its first Covid-19 community case in months on Sunday, a 56-year-old Northland woman who health officials described as "assiduous" in using the Covid tracer app with Bluetooth turned on.
Use of the app has spiked and the latest Health Ministry data shows about 20,000 new registrations and more than one million scans yesterday.
There are 2,505,796 registered users as of today.
However, the app has had lacklustre use in periods of zero active community cases.
Business associations say a Covid tracer discount is a novel way to motivate customers, and not something they've come across.
Restaurant Association of New Zealand CEO Marisa Bidois says the industry has had a challenging year and not many are in a position to offer discounts.
"But we've seen lots of other clever ideas including prominent signage, reminders on tables and menus, fun quips and messages," she said.
"Good on Tony's," said Heart of the city chief executive Viv Beck, "we hope they get plenty of business to cover the cost of the discount."
Asked about critics who may dismiss the discount as a marketing ploy, Henderson says he doesn't know that many people who would go out of their way for a 5 per cent discount.
But he knows the pandemic and its after-effects are the biggest threat the 57-year-old steakhouse has faced.
"We are nervous about having to go into another lockdown, so this is a positive step to avoid that."