A deal has been done on figuring out if tens of thousands of hospital and other health board workers are owed millions of dollars.
The 20 District Health Boards and unions are expected today to sign a three-part deal over how to assess if arrears are owed for leave and shift allowances.
It follows a three-year wrangle over the best way to rectify any breaches of the Holidays Act that come to light.
Scores of other public agencies and private companies have been caught up with difficulties correctly calculating holiday pay entitlements, and have liabilities in the many millions of dollars, and some, like MBIE, have spent millions more overhauling their payroll systems.
Arrears have already cost the police more than $45m since late 2015, and Corrections $16m.
For the DHBs it is still unclear how much any potential payout would be, or when it would happen.
"We think it will take quite a period of time to work through all the DHBs," joint board spokesperson Jim Green said.
But as a start DHBs have agreed to be assessed in small groups, and to have all begun looking at their liabilities by April 2020 at the latest.
They could not all start at once as there were not enough payroll providers to help them, Mr Green said
Council of Trade Unions president Richard Wagstaff said time would tell how significant any payroll fixes would be.
"We know that in other sectors it has for some individuals meant some quite significant payments, and for others not such big payouts," Mr Wagstaff said.
"But it's really important for the organisations too, they need to know that they've been paying people properly."
The Auditor-General last month told the DHBs to "urgently resolve" the payroll issue.
The boards have told the Health Ministry that paying arrears could have a significant financial impact on them.
Rough audits by MBIE at three DHBs had shown they had breached the Act, but gave no indication what the cost might be, Mr Green said.
Mr Wagstaff said DHB workers were frustrated by how long it was taking to sort out.