SR&ED filing deadline: when your claim is actually due

Your SR&ED filing deadline is not the day your T2 is due. It falls a full year after that, and it is one of the very few dates in Canadian tax where the Minister has no power to give you more time. For a corporation the date is 18 months after the tax year end. File on the day after, and there is no claim to argue about.

Most founders find this out the wrong way round. They assume the SR&ED claim rides along with the corporate return, so if the return is filed, the window must be closed. The opposite is true, and the misunderstanding costs real money in both directions.

At a glance

• Corporations get 18 months after the tax year end. That is the six months to file the T2, plus another twelve (CRA SR&ED Filing Requirements Policy, dated 28 January 2025).
• Individuals with a business get 17½ months after the calendar year end. Trusts get 15 months.
• Form T661 and Schedule T2SCH31 both have to be in by that date. Filing one without the other only half counts.
• Late means denied. Under subsection 37(12) an expenditure that misses the date is "deemed not to be an expenditure on or in respect of scientific research and experimental development".
• The stakes went up this year. Bill C-15 received Royal Assent on 26 March 2026 and lifted the enhanced 35% expenditure limit from $3 million to $6 million for tax years beginning after 15 December 2024 (CRA SR&ED news and updates).

How to work out your SR&ED filing deadline

Start with your tax year end. Add six months to get the T2 filing due date. Add twelve more to get the SR&ED reporting deadline. A 31 December 2025 year end gives you a T2 due 30 June 2026 and an SR&ED deadline of 30 June 2027. The rule comes from subsection 37(11), which sets the cutoff at 12 months after your filing-due date.

Off-calendar year ends need one extra step. If your year ends on the last day of a month, count to the last day of the sixth month. If it ends mid-month, count to the same day of the sixth month. CRA's own examples: a 28 February year end produces an August 31 filing due date and an August 31 deadline the following year, and a 6 January year end produces a July 6 due date and a July 6 deadline the year after.

So a company with a 28 February 2025 year end is up against 31 August 2026. If that is you and nothing has gone in yet, the comfortable part of the window is gone.

What actually counts as filing on time

You need both prescribed forms, complete, by the deadline. Form T661 carries the expenditures. Schedule T2SCH31 carries the investment tax credit. File the T661 alone and CRA's position is that you have met the filing requirement for the expenditures but not for the ITC, which is the part you wanted.

A few things that do not save you. A letter saying you intend to file is worthless, because the prescribed forms have not been filed. A claim submitted with estimates or with sections left blank may fail the requirement even though something arrived on time. If CRA reviews an incomplete claim before your deadline they will tell you what is missing, but you still have only until the deadline to fix it.

There is one merciful exception. Part 9 of the T661, the claim preparer information, is not subject to the reporting deadline. Getting it wrong risks a $1,000 penalty rather than the claim.

On timing, hand-delivered claims count on the day of delivery, mailed ones on the postmark, and internet-filed ones on the date the confirmation number is issued.

What happens if you miss the deadline

The claim is refused and there is no relief provision to fall back on. CRA's policy says that once the deadline passes the agency "cannot by law allow any additional time" to supply the prescribed information, and the claimant receives a letter saying the claim was not accepted. The expenditures get reclassified under the ordinary rules of the Act, without reference to the SR&ED provisions.

This is not CRA being unhelpful. Subsection 220(2.1) of the Income Tax Act does let the Minister waive a requirement to file a prescribed form. Subsection 220(2.2) then names subsection 37(11) and the SR&ED part of the investment tax credit definition as explicit exceptions. Parliament went out of its way to switch off the escape hatch for this one filing. The only extensions on record came from a ministerial order under the Time Limits and Other Periods Act (COVID-19), and none of them ran past 31 December 2020.

Put an illustrative number on it. A hypothetical CCPC with $600,000 of qualified SR&ED expenditures, comfortably inside its expenditure limit, earns a federal credit of $210,000 at the enhanced 35% rate, before any provincial credit. Miss the date and that becomes ordinary deductible spending. The engineering still happened and the work was still eligible on the merits, but for tax purposes it stops being SR&ED.

The same logic bites inside a live review. Once the deadline has passed you cannot add projects or expenditures, and you cannot substitute new amounts to replace ones CRA disallowed. Whatever you filed is the ceiling.

Filing your T2 without the claim does not close the door

If your reporting deadline has not passed, you can ask CRA to reassess a return you have already filed and include an SR&ED claim with it. The prescribed forms still have to be in by the deadline, but a return that has already been assessed is not the obstacle founders assume it is.

Which makes right now interesting. A calendar-year company that filed its T2 for the year ended 31 December 2025 by the June due date has until 30 June 2027 to put a claim on that year. That year also began after 15 December 2024, so it is the first one running under the expanded Bill C-15 rules. If you skipped the claim because you were not sure the work counted, that is a decision worth reopening rather than a door that closed in June. Software teams in particular tend to write themselves off too early, and what qualifies is broader than most founders expect.

A working checklist for the 18 months

• Write both dates on the calendar the day the year ends: the T2 due date and the SR&ED reporting deadline, six months apart.
• Collect contemporaneous evidence during the year, not at the end of it. Reconstructing time allocation from memory a year or more later is where claims get thin.
• Aim to file with the T2 at the six-month mark. CRA recommends it, and the extra twelve months is a buffer rather than a plan.
• If you are going to use the buffer, file at least 90 days before the deadline. That is the window CRA says it needs to flag deficiencies while you can still fix them.
• Confirm both forms went in. The T661 and the T2SCH31.
• Keep the filing confirmation. For internet filing the date on the confirmation number is your proof of filing.

Deadline tracking across several year ends goes wrong quietly rather than loudly. If you are handling claims for more than one company, put both dates somewhere structural instead of a calendar reminder. The SREDlog resource library goes deeper on the preparation side.

Frequently asked questions

When is the SR&ED filing deadline for a corporation?

18 months after the end of the tax year. That is 12 months after the T2 filing due date, which itself is six months after the year end. A 31 March 2026 year end means a T2 due 30 September 2026 and an SR&ED deadline of 30 September 2027.

Can the CRA extend the SR&ED reporting deadline?

No. CRA states it cannot by law allow additional time once the deadline has passed. Subsection 220(2.2) of the Income Tax Act specifically excludes SR&ED prescribed forms from the Minister's general power to waive filing requirements.

Can I file an SR&ED claim after I have already filed my T2?

Yes, as long as the reporting deadline has not passed. You request a reassessment of the return and file the prescribed forms containing the prescribed information by the deadline.

What happens if I file Form T661 but forget Schedule T2SCH31?

You meet the filing requirement for the SR&ED expenditures but not for the investment tax credit. If the T2SCH31 arrives before the reporting deadline, the ITC claim can still be processed. If it arrives after, the credit is lost.

Does the deadline move if it falls on a weekend?

Yes. If the reporting deadline lands on a Saturday, Sunday or a public holiday recognized by CRA, the claim is on time if CRA receives it, or it is postmarked, on or before the next business day.