How to File an SR&ED T661 Claim — 15 Steps (2026)

The Scientific Research and Experimental Development (SR&ED) program is Canada’s largest R&D incentive — up to 35% refundable federal ITC for CCPCs on the first $3M of qualified expenditures, plus Ontario’s 8% refundable Ontario Innovation Tax Credit (OITC) and 3.5% non-refundable Ontario Research and Development Tax Credit (ORDTC). This 15-step guide is the workflow Bader uses with Ontario tech, manufacturing, and construction firms filing SR&ED T661 claims in 2026, from eligibility screening through post-filing audit response.

1. Step 1: Screen the project for SR&ED eligibility

   Every SR&ED-eligible project must (a) advance scientific knowledge or achieve technological advancement, (b) address a technological uncertainty that could not be resolved through routine engineering or industry-standard practice, and (c) involve systematic investigation by qualified personnel through iteration, testing, and analysis. Document these three tests at project kickoff — CRA looks for contemporaneous evidence, not year-end reconstruction.

2. Step 2: Assemble the technical narrative and knowledge base

   For each project, prepare a written narrative addressing the five Guidance boxes on Form T661 Part 2: (i) scientific/technological uncertainty, (ii) hypotheses formulated, (iii) work performed, (iv) knowledge advancement achieved, and (v) records maintained. Contemporaneous engineering notebooks, code commit logs, test result spreadsheets, and design review meeting minutes are the highest-value evidence.

3. Step 3: Identify SR&ED-eligible salaries and time-track them

   Only time spent directly on eligible experimental development or supporting activities (analysis, testing, engineering design, mathematical analysis, computer programming) qualifies. Time on marketing, sales, general management, quality control (unless integral to SR&ED), and commercial production is excluded. Implement time tracking by project and activity — Toggl, Harvest, or a simple spreadsheet is sufficient if consistent.

4. Step 4: Choose the Traditional or Proxy method

   The Proxy Method uses a 55% flat rate applied to SR&ED wages to capture overhead — simpler and typically higher for R&D-heavy firms. The Traditional Method requires detailed schedules of overhead, materials consumed, and third-party contractor costs — better for firms with heavy material or contractor spend. Elect the method on Form T661 Part 3; the election is per year and can change year to year.

5. Step 5: Calculate qualified expenditures on Form T661

   Qualified expenditures include: (a) SR&ED salaries; (b) 80% of SR&ED contract payments to Canadian arm’s-length parties; (c) 100% of arm’s-length material consumed or transformed; (d) prescribed proxy amount (if Proxy elected). Non-arm’s-length contracts are limited to actual salary and material components. Third-party payments to Canadian universities are 100% qualifying at 20% federal rate (80% CCPC rate does not apply to non-arm’s-length or foreign work).

6. Step 6: Compute the federal Investment Tax Credit (ITC)

   For a CCPC with taxable capital under $10M in the prior year, the refundable federal SR&ED ITC is 35% on the first $3,000,000 of qualified SR&ED expenditures and 15% (partially refundable) thereafter. Non-CCPCs receive 15% non-refundable ITC. Complete Schedule 31 (T2SCH31) alongside T661 to claim the federal ITC.

7. Step 7: Add Ontario refundable OITC (8%) for eligible CCPCs

   Ontario Innovation Tax Credit provides an 8% refundable credit on the first $3,000,000 of qualifying expenditures for CCPCs with fewer than $50M in prior-year taxable capital and $500K in taxable income. File Ontario Schedule 566 with the T2. OITC reduces the federal SR&ED expenditure pool (grind for government assistance).

8. Step 8: Add Ontario non-refundable ORDTC (3.5%)

   Ontario Research and Development Tax Credit provides 3.5% non-refundable credit on qualified expenditures. Available to all corporations with an Ontario permanent establishment. File Ontario Schedule 508 with T2. ORDTC also grinds federal expenditure pool.

9. Step 9: Prepare the project financial schedule per project

   For each SR&ED project, prepare a schedule showing SR&ED salaries, contractor costs, material costs, proxy amount, and total qualified expenditures. This schedule must reconcile to the T661 totals and support the CRA reviewer’s ability to trace numbers back to your general ledger.

10. Step 10: Cross-check for government assistance and non-arm’s-length adjustments

    Any government assistance received on an SR&ED project (IRAP, NRC contracts, provincial grants) reduces the qualified expenditure pool dollar-for-dollar under s.127(18). Refundable credits like OITC and ORDTC also reduce the federal ITC base. Compile a schedule of all assistance and adjust the T661 accordingly.

11. Step 11: File Form T661 with the T2 return

    Form T661 must be filed within 18 months of the fiscal year end of the year the SR&ED was incurred (extended reporting deadline from the 12-month prescribed reporting deadline). Attach T2SCH31 (federal ITC), Ontario Schedule 566 (OITC), and Ontario Schedule 508 (ORDTC). File electronically via EFILE with your T2. Late-filed SR&ED claims are absolutely barred beyond the 18-month deadline — no ministerial discretion.

12. Step 12: Retain project documentation for CRA review

    CRA can review any SR&ED claim within four years of the notice of determination. Retain all technical narratives, engineering notebooks, code commits, test data, meeting minutes, and financial workpapers. Digital records with contemporaneous timestamps are stronger evidence than reconstructed post-hoc summaries.

13. Step 13: Respond to CRA review promptly and completely

    If CRA selects your claim for financial or technical review, respond within 30 days. Assign a project lead to interface with the CRA Research and Technology Advisor (RTA). Provide requested evidence in an organized binder. Understand the RTA is applying the CRA Eligibility Guidelines — cite them in your response.

14. Step 14: Assess reassessment options if the claim is denied

    A denied SR&ED claim can be objected to via Notice of Objection within 90 days of the notice of determination. Then within one year to Tax Court. Alternatively, restructure future project documentation to strengthen eligibility on subsequent claims. Engage an SR&ED specialist or tax lawyer for objections.

15. Step 15: Refresh SR&ED processes for the following year

    Post-claim, hold a lessons-learned session with engineering and finance. Update time-tracking templates, project intake forms, and contemporaneous documentation protocols based on the CRA reviewer’s feedback. The strongest SR&ED programs are the ones that build documentation into the normal engineering workflow rather than reconstructing at year end.

Frequently Asked Questions

What is the deadline to file an SR&ED T661 claim?

The extended reporting deadline is 18 months after the fiscal year end in which the SR&ED expenditure was incurred. Beyond 18 months the claim is statute-barred with no ministerial discretion. Best practice: file with the original T2 (6 months post year end) to accelerate refund cash.

How much SR&ED credit does an Ontario CCPC receive?

On the first $3M of qualified expenditures: 35% refundable federal ITC + 8% refundable Ontario OITC + 3.5% non-refundable Ontario ORDTC. The combined effective rate for a CCPC is roughly 41-42% of qualified expenditures after inter-credit grinds. Beyond $3M, the federal rate drops to 15%.

Can a foreign contractor cost qualify for SR&ED?

No. Only Canadian-performed work qualifies. Payments to foreign contractors are not qualified expenditures under s.37 and s.127.

Are software companies eligible for SR&ED?

Yes, if the project meets the three eligibility tests — technological uncertainty, systematic investigation, and knowledge advancement. Routine application of well-known frameworks, standard bug fixing, and commercial feature implementation do not qualify. Novel algorithms, systems research, and performance optimization requiring experimentation typically do.

What documentation does CRA expect for an SR&ED claim?

Contemporaneous engineering notebooks, code commits with descriptive messages, test result spreadsheets, design review minutes, project plans with hypothesis statements, and time tracking by project and activity. CRA specifically discourages year-end reconstruction and looks for evidence created during the SR&ED work.

Authoritative Sources

• CRA — Form T661 Scientific Research and Experimental Development (SR&ED) Expenditures Claim
• CRA — SR&ED Program overview
• Insight Accounting CPA — SRED Tax Credit Canada 2026

Expanded technical guidance

Common pitfalls in an SR&ED T661 claim

• Contemporaneous documentation gap. CRA reviewers expect real-time technical narratives dated within the fiscal year — not retrospective write-ups. Set up a weekly SR&ED log at project start; retroactive documentation is a common reason for claim denial.
• Contract R&D vs SR&ED expenditure misclassification. Payments to arm’s length contractors are eligible only for 80% of the qualifying portion under ITA s. 127(9). Full inclusion is a common error.
• Missing 12-month SR&ED reporting deadline. The T661 must be filed within 12 months of the T2 filing due date (18 months after fiscal year-end). Missing this is fatal — no extensions available.

Forms, filings, and deadlines

Core filing is Form T661 (SR&ED Expenditures Claim) attached to the T2. Ontario provincial claim uses Form T2 SCH 508 (Ontario Innovation Tax Credit — OITC 8% refundable) and Form T2 SCH 566 (Ontario Research and Development Tax Credit — ORDTC 3.5% non-refundable). Federal ITC calculation: Form T2 SCH 31 (Investment Tax Credit for CCPCs — 35% refundable on first $3M of qualifying SR&ED expenditures, 15% non-refundable on excess). Guidance: CRA Application Policy SR&ED 96-01, Income Tax Folio S1-F5-C1 (Related Persons and Dealing at Arm’s Length), and CRA’s T4088 SR&ED Claim Guide.

Worked example — CCPC with $500K qualifying expenditures

Toronto SaaS CCPC has $500,000 of qualifying SR&ED wages and materials. Federal ITC = 35% × $500,000 = $175,000 refundable. Ontario OITC = 8% × $500,000 = $40,000 refundable. Ontario ORDTC = 3.5% × ($500,000 − OITC portion) = ~$16,100 non-refundable. Total cash-refundable = $215,000 (matches the Mr. B case study).

Worked example — expenditure over $3M cap

Same CCPC scales to $4M qualifying expenditures. First $3M taxed at 35% refundable federal ITC = $1.05M. Excess $1M at 15% non-refundable = $150K (carried forward if not usable). Ontario OITC: $4M × 8% = $320K refundable (subject to $3M expenditure cap coordination). Model the excess-cap treatment carefully in the T661 to preserve carryforward.

Worked example — contract R&D with arm’s length developer

CCPC pays $100K to an arm’s length contract developer for SR&ED work. Eligible portion for ITC calculation = 80% × $100K = $80K under s. 127(9). Federal ITC = 35% × $80K = $28K. Failing to apply the 80% factor overstates the claim and triggers CRA reassessment interest.

Related Insight resources

Ontario tech founders should review the Mr. B SaaS startup case study where Insight recovered $215K in refundable OITC + federal ITC. The pillar on SR&ED tax credit eligibility and claim amounts covers the 2026 rate structure (Federal 35%/15% + Ontario OITC 8% + ORDTC 3.5%). If your SR&ED work is embedded in a broader CCPC structure, pair this guide with how to preserve the CCPC small business deduction.