ANZ Bank says KiwiSavers are missing out on about $400 million in tax credits because they are not contributing enough to their retirement accounts.
The Government pays up to $521 in tax benefits to each KiwiSaver every year, but they must contribute at least $1042 to get the full benefit.
ANZ Wealth managing director John Body said his bank's analysis suggested only 56 percent of potential tax credits were paid out in the year ended June, although that was up from about 50 percent the previous year.
This year, ANZ contacted its KiwiSavers to remind them of the available benefits and, as a result, members of the bank's three Kiwisaver schemes made $24 million of additional voluntary contributions.
That meant ANZ's KiwiSavers received $33 million more in tax credits.