buksoSR&ED research development credit T661 deadline
Not tax advice. General bookkeeping information only, checked against the official sources linked below (Canada Revenue Agency, IRS, provincial governments and Justice Laws) on Oct 17, 2026. Rules change; check with your accountant before you file.
Canada
The SR&ED program gives tax incentives for qualifying research and experimental development work done in Canada. You claim it on Form T661 (corporations also file Schedule 31). The claim must reach the CRA within 18 months after the end of the tax year the work was done in, and changes are not accepted after that deadline.
Official source: canada.ca