What happened: OSFI says four mortgage insurer returns and the MICAT capital return change from Q1 2027.
Who’s involved: OSFI and Canada’s federally regulated mortgage insurance companies.
What’s at stake: New 2027 versions of the MI3, MI4, MI5 and MIPROV returns, plus the MICAT return.
Why it matters: Reporting teams keep current forms for Q4 2026, then switch to IFRS 18 layouts.
Where it stands: Letter dated October 22, 2026; updated returns and instructions are already on OSFI’s website.
Start with the easy part. Reporting teams at Canada’s federally regulated mortgage insurers will file their Q4 2026 numbers on the same forms they already know.
Then the forms change.
In an October 22, 2026, letter to company chief executives, the Office of the Superintendent of Financial Institutions said four regular returns need changes once IFRS 18 kicks in for Q1 2027. Those are the core financial quarterly return, the supervisory quarterly and annual returns and the provincial return - MI3, MI4, MI5 and MIPROV, if you speak OSFI.
The capital return is getting a refresh too. OSFI says it has changed the Mortgage Insurer Capital Adequacy Test (MICAT) return and its filing instructions for Q1 2027.
IFRS 18 has been on insurers’ radar for a while. In September, Insurance Business reported that OSFI had finalized new IFRS 18 return templates for federally regulated insurers.
Here is the reassuring bit. OSFI has said the standard changes how insurers present and disclose their results, not how they measure assets or liabilities, with the profit-and-loss statement reorganized into operating, investing and financing categories.
Timing depends on the calendar. OSFI says its updated insurer returns take effect January 1, 2027, for companies with a December 31 year-end, and November 1, 2027, for those with an October 31 year-end.
Nobody has to hunt for the paperwork. The 2027 returns, instructions and supporting documents are already on OSFI’s website, with Section VI of the instructions summarizing the changes, and the current 2026 versions are still posted.
The letter doesn’t say what changed inside the MICAT return. Separately, OSFI’s final 2027 MICAT guideline, which sets the minimum capital mortgage insurers must hold, trims the capital charge for one corner of the market.
It creates a new category for low-rise multi-unit residential construction, which OSFI defines as projects of fewer than seven storeys and 200 units. The base risk weight for those projects drops from 150% to 130%, while high-rise projects stay at 150%. The guideline takes effect January 1, 2027.
A few loose ends remain. OSFI says updates to its validation rule reports will be posted once they are available within its RRS system. The letter, signed by chief data officer Andrew Miller, also flags 2026-27 changes to forms from the Canadian Council of Insurance Regulators.
Filing questions go to OSFI’s Returns Administration, and anything else goes to each company’s lead supervisor.
Calendar-year mortgage insurers close out 2026 on the old layouts, which leaves a full quarter to dry-run the new 2027 returns before the first one is due.
