Compliance

Founder-Friendly SR&ED Filing Deadlines

The SR&ED filing deadline is 12 months after the T2 filing due date — not your fiscal year-end. Here's what that means for your claim timeline, and what happens if you miss it.

Sophie Lamarche · Policy & Compliance Desk 2026-04-29 4 min read

There are no extensions. None.

Most tax filings in Canada have some flexibility — file late, pay a penalty, get on with it. SR&ED is different. Miss the deadline and that year's claim disappears. There is no late-filing mechanism. CRA cannot grant an extension. The window closes and does not reopen.

This is the most important compliance fact about SR&ED, and it's the one founders most often underestimate — because they're used to a tax system with more give than this one.

The formula: T2 filing due date + 12 months = SR&ED deadline. For most corporations, the T2 is due 6 months after fiscal year end. That makes the SR&ED deadline roughly 18 months after your fiscal year closes.

Practical deadlines by fiscal year end

  • December 31 year end → T2 due June 30 → SR&ED deadline June 30 (following year)
  • March 31 year end → T2 due September 30 → SR&ED deadline September 30 (following year)
  • June 30 year end → T2 due December 31 → SR&ED deadline December 31 (following year)
  • September 30 year end → T2 due March 31 → SR&ED deadline March 31 (following year)
Critical detail

The 12-month window runs from the T2 filing due date — not the date you actually filed the T2. Filing your T2 early doesn't compress the SR&ED window. You still have until 12 months after the due date.

When to actually start

The deadline is 18 months out. That sounds comfortable. It isn't — because SR&ED preparation takes time, and the bottleneck is almost always the CPA review, not the initial drafting.

  1. Minimum viable timeline: start 3–4 months before the SR&ED deadline. This leaves time for T661 narrative drafting, CPA review, revisions, and integration with the T2 filing. Some CPAs need more runway for complex claims.
  2. Better: begin documentation habits at the start of your fiscal year (see: the evidence habit article), so the evidence base already exists when you need it.
  3. Best: treat SR&ED as an ongoing practice, not a year-end project. The T661 narrative draft should take hours, not months, if your documentation is in order.

Treating SR&ED as a year-end task is how companies miss the deadline. CPA availability in Q4 is constrained. Evidence reconstruction takes longer than expected. Starting three months before the window closes is already cutting it close.

Prior years and multiple claims

Each fiscal year has its own T661 and its own deadline. If you have qualifying work from multiple prior years that you haven't claimed, you can prepare and file them simultaneously — provided each year's deadline is still open.

There is no mechanism to recover a missed year or consolidate unclaimed SR&ED across periods. If you're uncertain whether a prior year's window is still open, a CPA can confirm the status based on your T2 filing history.

This guide provides general information about SR&ED filing deadlines. Specific deadlines depend on your fiscal year end, claimant type, and other factors. Always verify your specific deadline with a qualified Canadian CPA.

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