More than 211,000 people, including schools and even a Cabinet minister, are owed a share of $78 million of unclaimed cash held by Inland Revenue dating back to 1973.
The money is not tax refunds but includes cash from banks, finance companies, trusts and even insurance proceeds, or unpaid wages and salaries.
It has been transferred to IRD by organisations that cannot track down the owner, and most people are not aware it is there.
IRD has posted the latest 18,500 on its website, dating from 2005, and they include some familiar names.
The Minister of education, Hekia Parata, and her husband Sir Wira Gardiner are listed as being owed $1325.
A spokeswoman said Ms Parata had no idea she was owed the money and would ask Sir Wira to look into it.
The largest amount shown is $371,664 owed to Mr K Nakayama.
But 193,000 potential claims, worth about $57m, are in paper- based files and cannot be searched online. Anyone who thinks they may be one of those must provide their details, including their tax number, to the IRD who will check their files.
But Labour revenue spokesman David Clark said the department should make it easier.
"When voluntary income tax compliance is dropping and customer satisfaction surveys indicate a growing dissatisfaction ... the department could do a good deal worse than making details of all monies available through an online service. It would be viewed as a gesture of good faith."
Revenue Minister Peter Dunne said yesterday he was prepared to look at the cost and feasibility of putting all the information online.
It might have been too difficult or was not "top of mind".
"But I don't think we should be withholding it from people it belongs to. When the boot's on the other foot we are quick enough to claim it."
A spokeswoman for IRD said no- one from the department was available to be interviewed about the unclaimed money.
But in a statement IRD said it "encourages anyone who thinks they may have a claim to contact us" either in writing or by email to email@example.com.
Under provisions of the Unclaimed Monies Act 1971, funds left untouched for more than six years are required to be paid to Inland Revenue.
"It's the responsibility of the institution holding the funds to make every effort to locate the proper owner of the money. But sometimes, with people moving around and changing jobs, this can be difficult."
Meanwhile, Rabobank has established a "yourcashstash" website to make it easier to search the latest 18,500 records.
Rabodirect general manager Mel Templeton said it seemed legislation prevented IRD from advising individuals and organisations they were owed the money.
But Mr Dunne said he could not see anything in law that prevented IRD telling people they were owed money.
Interest is not paid on the unclaimed money.
Rabobank estimates only $2m, or 2.5 per cent of unclaimed cash, had been paid to its owners. Fairfax NZ
- Taranaki Daily News
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