Assistant Treasurer and Minister for Small Business Kelly O'Dwyer.

The federal government wants to reunite people with their lost dollars from forgotten life insurance, shares and other investments, including $650 million in unclaimed bank accounts.

“People are often pleasantly surprised when they search for their names using ASIC’s MoneySmart Unclaimed Money online search,” Assistant Treasurer Kelly O’Dwyer said in a statement on Wednesday.

As of December 31, 2015, a new law came into effect which changed the definition of unclaimed money as being funds that had been dormant for a period of seven years.

Labor had changed the defining period from seven years to three years back in 2012, but reversed its position when the laws were again debated in parliament in September last year.

Shadow assistant treasurer Andrew Leigh said the opposition recognised the three-year time frame had ended up capturing some active accounts.

It was important to get the balance right between protecting the value of savings and ensuring accounts are not claimed incorrectly, he told parliament at the time.