A parliamentary inquiry has recommended the Senate pass laws aimed at simplifying the way welfare recipients report their income.
But stakeholder consultation is needed and a review should be undertaken a year after the laws are implemented, a report tabled on Thursday said.
The changes will cost $30 million over three years, according to figures published by the inquiry on the same day.
More than $5 billion is overpaid to welfare recipients each year and the accuracy of reported employment income is a major contributing factor, the figures show.
The Morrison government wants to slash welfare overpayments by changing the way recipients report their incomes.
Rather than submitting an estimate based on their wage and number of hours worked, people would report their actual incomes.
"The committee recommends that further targeted consultation and user testing is undertaken prior to the commencement of the (new system)," the report said.
It said the government should commit to a review of the rollout 12 months after it starts, tabling its finding in parliament.
The Greens have suggested delaying a proposed July 1 start date pending testing of the new system.
Services Australia, the new agency overseeing the welfare system, will be given $10 million a year until 2020/21 to fund the transition.
Costs will cover educating recipients and administrative changes.
Services Australia has pushed for a July 1 start date.
"Any delay in the passage of legislation will delay the significant benefits to income support recipients," it said.
Welfare advocates have called on the government to delay its rollout and consult with stakeholders to prevent another robo-debt "disaster".
"There's no need to rush this bill," the Australian Council of Social Service told the committee this week.
"To compare what happened with robo-debt, there was no consultation with experts at all."
The bill is scheduled for debate in the Senate next week.
Australian Associated Press
