Residents across the Riverina and MIA are being encouraged to check whether they are owed any of the millions of dollars waiting to be claimed with Revenue NSW.

Minister for Finance and Small Business Damien Tudehope said more than $146 million in "forgotten money" was sitting with Revenue NSW, including cash from share dividends, trust accounts, deceased estates, overpayments and a range of other sources.

"There are more than 5000 unclaimed items worth more than $1 million in the Riverina region alone," Mr Tudehope said.

"The value ranges from $20 in share dividends to a trust fund worth more than $1 million."

It is not just in Griffith that residents could be overlooking a cash windfall.

In Wagga, there's 1523 residents owed $378,990, there's $66,364 which needs to be claimed by 66 Leeton residents.

115 residents from Junee have overlooked cash totalling $28,181, while 39 Coolamon residents have overlooked a total of $6377.

There is $12,553 waiting for 73 Gundagai residents, while 126 people at Lockhart are owed a share of $41,174.

"Cost of living is a major issue facing families and households across the state, which is why we want people to check their eligibility. It only takes a few minutes and you could walk away with extra money in your pocket," Mr Tudehope said.

Revenue NSW holds more than 414,000 unclaimed items from private companies, state trustees, local councils and government agencies that cannot be returned to owners because their contact details are out of date.

"Finding out if you are eligible is quick and simple. If you enter your name into the free search tool on the Revenue NSW website you can see if you have an eligible claim. If you do have a claim, notify Revenue NSW and collect your money," Mr Tudehope said.

"You can also make an appointment at a Service NSW centre with a cost of living specialist and they can help you check your eligibility for any unclaimed money, as well as other rebates and incentives including Active Kids vouchers, CTP refunds, and free registration for regular toll users."

The government will hold the money indefinitely until it is claimed. To find out if you are eligible, visit https://www.apps08.osr.nsw.gov.au/erevenue/ucm/ucm_search.php