A former McDonald's worker was shocked to discover that the company had calculated she had been overpaid more than $18,000 in holiday pay.
The fast food company is paying out holiday pay to tens of thousands of staff who had their entitlements calculated incorrectly.
In November 2019, Unite Union announced it had reached a deal with McDonald's to go back 10 years to reimburse employees over a payroll botch-up.
McDonald's is one of hundreds of companies caught up by payroll systems incorrectly calculating holiday pay.
Unite Union national secretary John Crocker told RNZ this week that some staff had had their payouts reduced by calculations that they had been overpaid, too.
In a statement, Crocker said: "We urge all current and former McDonald's employees to contact McDonald's in writing and 'withdraw your consent to deductions' and tell them you want the full figure of underpayments."
One woman said that had applied to her in dramatic fashion.
She had received a statement saying she had been underpaid $3600 but overpaid more than $18,000.
She said she had been told it had accumulated over about 12 years of employment at a number of McDonald's outlets, owned by the same overall company.
"I had a good relationship with my previous employers. I am baffled by this. I have yet to be contacted by McDonald's regarding this but expect an email soon."
She said she did not think she had much time off over her employment, but the information was not transparent or easy to understand.
"None of it really makes sense."
She said the website information did not match the statement she received, which also did not line up with what her former employer told her in an email. "It's very confusing. I need someone to tell me I don't have to pay it. I had holidays, I got paid for holidays, I don't understand how I could end up overpaid."
A McDonald's spokesperson said staff who had been overpaid would not be required to pay it back.
"There is an 'offsetting' approach approved by MBIE, given it's common for people to have cases over under and overpayment when payments are recalculated for the remediation period. Where the net impact is that a person has been paid too much we're not expecting them to pay anything back to the employer. The only upside in the remediation is to benefit the employee. Also, to note, if they were paid too much, they already have that money from the payment at the time… no one who's been overpaid would get a bill/claim back from the franchisee who employed them."
Jim Roberts, a partner at law firm Hesketh Henry, said there were parts of the law that were difficult, but a fundamental problem for many large employers was the way that their payroll providers calculated holidays.
"Every one of those systems that I've had access to calculates holiday son an hourly basis… but the act provides for holidays in weeks.
"If you've got someone whose pay and hours don't move, then for the most part you won't have a problem, but if your hours change either on a permanent basis or temporary, or variable, or your pay changes, then the software immediately has a problem."
It was also possible that the right amount of time might be allocated but the pay assigned to it could be wrong.
He said problems could compound because if a holiday was paid wrong, every subsequent holiday in the next 12 months could end up calculated on a basis that included the incorrect holiday assessment.
He said McDonald's was the sort of workplace that would have more difficult. "Very few people work a perfect set of weekly hours… most employees are on some form of shift so it's less likely their hours are going to fit nice and neatly."
The government is working through a process it says aims to simplify the law.