Non-essential businesses that flout the lockdown rules and remain open will be fined and shut down immediately, authorities warn.
The Ministry of Business, Innovation and Employment is sending the message to businesses everywhere that only firms considered to provide a necessity of life, for example, are an essential service as of 11.59pm on Wednesday.
Today's comments follow widespread confusion about what constitutes an "essential" service - after department store Farmers publicly stated it would stay open.
MBIE deputy chief executive Paul Stocks spoke about the issue on Newstalk ZB's Mike Hosking Breakfast show this morning:
"We're not doing a Level 4 lockdown because it's not important. We've got one chance to eradicate Covid-19," Stocks said.
Businesses and jobs that could open during the country's four-week lockdown will do so because they provide services for health, safety, welfare and essential infrastructure.
Up to 15 sectors of society have been identified as being essential services; including supermarkets, pharmacies and banks.
Self-service laundry facilities and dairies will also remain open - on a "one in, one out" basis and the 2m distance rule to be adhered to at all times.
Stocks confirmed that smaller shops - including fruit and vegetable store operators - would be closed during the month-long lockdown.
Butchers were also not considered an essential service and would be closing their doors after today too. The same goes for liquor stores.
The Warehouse will shut its doors during the lockdown period - despite initial reports that it was to remain open because it was considered to be an essential service.
Stocks acknowledged, however, that some areas where supermarkets or shops were limited would be looked at on a case-by-case basis.
"If you are part of the supply chain...then yes, you are an essential service.
"We want to make sure everyone has access to food."
Farmer chief financial officer Michael Power said the department store planned to stay open.
"Our stores, including our online store, support office and distribution centre are open for business as usual, with our teams taking additional steps to ensure everyone's safety."
Staff had been advised to stay at home if they felt unwell and to seek medical advice. The same message applied for customers, Power said.
People are being encouraged to check in on the dedicated Covid-19 website for more information and an 0800 number is due to be set up for businesses to call.
However, officials yesterday said that if you are unsure that you are an essential business, then you probably are not one.