Overpayment recipients included 1,522 prisoners, 391 dead people and 434 children too young to be eligible.
The auditor general found that $4.6 billion in payments for programs such as CERB were made to individuals who were ineligible.
An estimated 1.2 million people aged 18 to 24, living with their parents in households with income of at least $100,000, received the GST credit in 2021.
According to forecasts, federal spending will be $89.2 billion higher than previously projected for 2022/23 and $80.7 billion higher in 2023/24.
The federal government continues to run and plan for substantial budget deficits.
Compared to fiscal year 2019-20, total federal spending in 2022-23 will be approximately 27 per cent higher.
According to the budget, federal spending will reach $434.3 billion this year, more than a two-thirds increase in less than a decade.
Under the old classification, program spending would have been more than $10 billion higher.
According to projections, the federal debt will reach nearly $2 trillion in 2026-27.
This year the federal government expects to spend $52.8 billion more than it has in revenues.