Health New Zealand Te Whatu Ora (HNZ) is scrambling to pay about 5500 staff in Waikato after a payment glitch.
Waikato Hospital health worker Helen, who did not what her surname used, told RNZ she felt embarrassed having to ask for money.
"I've had to borrow money just so I could park my car and make sure I could get my car out of the car park this afternoon after work," she said.
"I've had to call the banks to make sure that they're aware that money will not be available for my loans, I've had to let my landlord know that I won't be able to pay my rent today due to not having enough money in the account.
"At this stage, if money doesn't go through overnight, I'm not 100 percent sure that I can come to work tomorrow because my petrol light is also on."
HNZ put the problem down to an error in a rostering system used to calculate payments.
"This issue has now been resolved, and all impacted staff will be paid by the end of today," Robyn Shearer from its people and culture team said.
"We are confident we have addressed the underlying reasons, and we have reduced the likelihood of this reoccurring."
Staff were informed about the problem in a memo, Helen said.
"They have told us that the hours have been sent to the bank at about midday today, and they're hoping that the money will come in overnight.
"But there's no guarantee that the amount will be correct."
Colleagues were in similar situations, Helen said.
"Most of them have been on the phone to the banks and changing mortgage payments and hoping that we don't get stung with fees and dishonour payments or defaults on loans and things like that.
"It's horrifically stressful at the moment."
The pay glitch was frustrating, but she loved her job.
"And if I can be here tomorrow, I will be."
The Public Service Association (PSA) called on HNZ to do an urgent review and said the error was a widespread failure.
The pay glitch affected about half of health workers in Waikato, it said.
"Workers turned up and did their jobs, caring for patients, keeping hospitals running, and they deserved to be paid on time," the union's national secretary, Fleur Fitzsimons, said.
"A payroll failure of this scale is not a minor inconvenience - it causes real hardship."
Apologies from HNZ were not enough and IT failures had become a recurring feature of the public health system, Fitzsimons said.
Health Minister Simeon Brown acknowledged staff who worked through the night to fix the problem.
"I know this situation will be frustrating for those affected, and getting it resolved so staff are paid as soon as possible is the priority."
His office said the minister was waiting for HNZ's review into how the error happened.
