There are some concerns on the federal budget watchdog's mind.
Four provinces have not received any payments over the past decade.
The people at the top hold roughly $3 trillion between them.
But the money Canadians get back won't be as much as projected last year.
The change will mean that 900,000 people won't have to pay any income tax.
He says the CRA isn't providing his office with enough detailed information.
PBO estimates the project is worth between $3.6 billion and $4.6 billion.
He's spent more than 20 years in the public service.