In November 2019, Unite Union announced it had reached a deal with the fast food giant to go back 10 years to reimburse employees over a payroll botch-up.
McDonald's was one of hundreds of companies caught up by payroll systems incorrectly calculating holiday pay.
On its website this week, the company said it had been given approval by the Ministry of Business, Innovation and Employment to begin remediation.
It said current and former staff who worked during the remediation period between 2009 and 2019 should go to an online portal to check their payment.
At the time of the union deal, Unite said as many as 60,000 McDonald's workers and millions of dollars would be involved in the process.