False error codes and repeat tax slips in CRA system create confusion ahead of April 30 deadline
Two more problems have emerged during the Canada Revenue Agency’s (CRA) troubled 2025 tax season: duplicate tax slips appearing in online accounts and error codes preventing electronic submissions, The Globe and Mail reports.
Several accountants said they found identical tax slips—such as T4s and T4As—appearing in their clients’ CRA accounts. T4s record employment earnings, while T4As cover pension and other income sources.
The CRA also confirmed that some users trying to submit returns electronically are encountering error codes that temporarily block them from filing.
“These shouldn’t happen, the system should be a bit more robust and checked,” said Steven Watson, executive director of the EFILE Association of Canada, referring to the error code issue.
The CRA had previously warned that a system update introduced in January led to challenges for some employers and financial institutions trying to upload tax data.
This update rolled out stricter slip verification protocols, and resulted in many taxpayers missing slips in their CRA accounts. It is not yet clear if this same update is behind the duplicate slips or the faulty error codes.
Ryan Minor, director of taxation at Chartered Professional Accountants of Canada, said the CRA acknowledged a limited issue with duplicate slips and promised to correct it internally.
According to Minor, the agency also asked issuers not to remove the duplicate slips themselves.
The CRA did not respond to a request for comment by deadline.
Watson added that tax preparers have warned some slips in CRA’s portal are incomplete compared to their paper counterparts.
He recommended that Canadians rely on the slips they receive directly from employers or banks and manually cross-check CRA records.
Tax professionals warned that missing slips could lead to underreported income if users rely on the CRA’s auto-fill feature.
Conversely, duplicate slips might cause users to report too much income and overpay.
Hugh Neilson, director of taxation services at Kingston Ross Pasnak LLP, said those who spot duplicate slips should file based on actual income and contact the issuer to report the issue.
On April 14, the CRA posted an update confirming that its system is triggering incorrect error codes in tax software, affecting both professionals and individual filers.
The agency is tracking these cases and working to resolve them. It stated that if the problem is unresolved by the April 30 deadline, it will proactively waive penalties and interest for affected taxpayers.
“To be eligible for relief, an impacted filer must have attempted to submit the return electronically on or before April 30th, received the specific error code, and was unsuccessful in resolving the error code despite taking the appropriate corrective action,” the CRA said.
Watson said that this process burdens tax preparers, who must monitor each failed submission and keep trying until the message is resolved. “It’s not an ideal protocol,” he said.
Minor also expressed concern that if CRA fixes the issue just before the deadline, such as on April 29, professionals will have to resubmit returns quickly, adding to the stress.
“They’re going to provide relief if the issue is not resolved before April 30, but what if they resolve it, for example, April 29,” Minor said. “Then practitioners have to go and file these returns again – this adds another layer of stress.”
As per Investment Executive, these duplicate slips have already affected Old Age Security clawback calculations for some individuals, raising the stakes for seniors and pension recipients.
According to Advisor’s Edge, tax professionals have received no indication that CRA will extend the April 30 filing deadline, despite ongoing technical issues.
The CRA continues to update its guidance on frequently reported errors through its official website, including how to handle common e-filing problems.
