Tony Black of Black Steel received $239,000 as part of the emergency payout for businesses to pay staff during lockdown.
He said the payout should not have been given all at once.
"Three months in one go, it made us all assume New Zealand was going to be in compulsory lockdown for three months, and that's what you have to base your decisions on in business is the worst-case scenario and hope for the best."
Black said the shutdown has so far cost him about $80,000, and he is planning to have his 40 employees back at work on Tuesday, when tens of thousands of workers in the construction, restaurant and manufacturing industries are expected to return to work under alert level 3 conditions.
"I'm going to use it to pay my staff and keep my cashflow up and ensure that my guys have still got a job in five months' time."
Black said his business, which does steel fabrication for residential construction in the Auckland area, had outgoings of $190,000 a month for rent, insurance and wages alone.
"The amount of money I need to keep running is massive."
He said the uncertainty of the coronavirus pandemic made it hard to make financial plans.
"I don't know what business we will have in a few weeks time, none of us had a crystal ball when we applied for it."
Black said operating in level 3 would present challenges, and staff would inevitably have to take more sick days.