There are calls to extend this year's tax deadline amid a federal public service strike that some say is making it hard to file on time, but experts are still urging Canadians to make every effort to file by May 1.

An online petition by Ottawa accountant Eric Saumure calls on Ottawa to push the filing deadline to June 15, from May 1. The site had collected more than 25,000 signatures by early afternoon Tuesday.

Saumure said the job action has reduced staff for a Canada Revenue Agency help line, forcing some callers to wait hours for advice and possibly jeopardizing their ability to file on time.

He said lower-income taxpayers who need help but don't have an accountant would be most vulnerable.

“I kind of see this as if you're writing an exam in school but the professor just doesn't let you ask questions,” Saumure said.

“And if you make a mistake, there's a penalty. There's a financial penalty. And so that's just not fair for Canadians.”

About 159,000 federal public servants with the Public Service Alliance of Canada are on strike, including 39,000 CRA employees, as union representatives negotiate with the government over wages and work flexibility.

The CRA says on its website that tax returns filed digitally will largely be processed automatically “without delay.” So far, it says about 95 per cent of the 17 million people who have filed did so using self-service digital options.

It adds that the tax filing deadline has not changed and that Canadians should ensure their returns are filed by May 1, along with any owed payments.

Given the vast majority of digital tax filers, Vivian Leung of the Chartered Professional Accountants of Canada doubted the strike would delay assessments so much that a later deadline is needed.

“I would say 90 per cent of the basic services that Canadians will need to file their return is available online,” she said.

“So I don't really see a strong, strong need (to extend the deadline) at this point for the massive majority of Canadians.”

A media rep for the CRA said by email that if “circumstances beyond the control of a Canadian or business” cause them to file late “the CRA may provide relief from penalties or interest” on a case-by-case basis.

Still, the agency says on its website that many services “are expected to be delayed or unavailable,” particularly in processing some income tax and benefit returns filed by paper.

Saumure said Canadians who cannot file electronically - for instance because they don't have access to a computer or are not computer literate - risk a delayed refund by mail if they are entitled to money back. Those who owe but can't file on time because they're waiting for CRA advice risk late fees and interest.

“It's really impacting the people who don't have the money to hire a knowledgeable accountant. They're the targeted people here. Oftentimes, those are lower-income Canadians or in many cases, the average Canadian,” he said.

Kirstin Beardsley, CEO of Food Banks Canada, said Canadians who don't have access to a computer or need tax advice can find help at free tax clinics run by hundreds of community organizations across the country.

She said Food Banks Canada is increasing its involvement with the Community Volunteer Income Tax Program this year to encourage more people to file on time.

She said some food bank users are hesitant to file taxes because of government skepticism or the fear that doing so means they would owe money. But she said Food Banks Canada helped users submit 4,500 tax returns last year, resulting in a little more than $18 million in refunds.

“For folks who have multiple barriers in place already, having that connection to the community-based clinic is critical,” said Beardsley.

Leung said taxpayers can always amend a return that has already been filed if needed. And if you expect to owe money on a return you're not ready to file by May 1, Leung suggested paying in advance to avoid extra financial penalties.

“You can put in a payment now just to cover yourself,” she said.

“If you're not sure, file based on what you think it is and as you find out later on because you finally get a hold of someone, at least you won't have that late filing penalty.”

This report by The Canadian Press was first published April 25, 2023.