The client
A household in Victoria whose CMHC-insured mortgage matured, with 20 years remaining amortization and no plan to increase either the loan amount or the remaining term — the textbook definition of a straight switch to a new lender at renewal.
They had read, correctly, that OSFI stopped requiring a stress test on some straight switches at renewal. What they had not confirmed was whether that change applied to their own mortgage — and it does not.
Mortgage status
CMHC-insured, at maturity
Straight switch: no increase to loan or amortization
Remaining balance
$430,000
20 years remaining amortization
Household income
$9,600/month combined
Car loan $480/month; clean credit
Carrying costs
Tax $410/mo; heat $140/mo
Lender-standard estimates
Lender A offer
5.29% contract rate
Illustrative — not a quote
Lender B offer
4.49% contract rate
Illustrative — not a quote
The problem
OSFI’s November 21, 2024 exemption removes the requirement to apply the minimum qualifying rate to a straight switch — but only when the mortgage being switched is uninsured. This mortgage is CMHC-insured, so the exemption simply does not reach it, no matter how straightforward the switch itself is.
Lender A's offer, tested at the qualifying rate
- ▸5.29% contract rate produces a 7.29% minimum qualifying rate
- ▸GDS: 40.9% — against CMHC’s 39% maximum
- ▸TDS: 45.9% — against CMHC’s 44% maximum. Declined.
The mortgage stress test’s qualifying-rate history shows the minimum qualifying rate has applied to insured mortgages consistently, unaffected by the 2024 uninsured-switch carve-out. The gap between what the client expected and what actually applied was the entire problem here — not the borrower’s ratios themselves.
The numbers
Because this file is insured, the minimum qualifying rate applies in full at the switch, exactly as it would on a new purchase. The only variable left to work with, once that was confirmed, was which lender’s contract rate produced the lowest qualifying payment.
| The switch, tested against two lenders | Amount |
|---|---|
| Remaining balance | $430,000 |
| Remaining amortization | 20 years |
| Lender A qualifying rate (5.29% + 2%) | 7.29% |
| Lender B qualifying rate (4.49% + 2%) | 6.49% |
| Lender / rate basis | Payment | GDS | TDS |
|---|---|---|---|
| Lender A, qualifying rate (7.29%) | $3,381 | 40.9% ✗ | 45.9% ✗ |
| Lender B, qualifying rate (6.49%) | $3,182 | 38.9% ✓ | 43.9% ✓ |
| Lender A, contract rate alone (5.29%) | $2,893 | 35.9% | 40.9% |
| Lender B, contract rate alone (4.49%) | $2,708 | 33.9% | 38.9% |
The bottom two rows are what the file would have shown had the straight-switch exemption applied — comfortable on either lender’s contract rate alone. Because it does not apply, only the top two rows matter, and the difference between them is entirely the 0.80-point gap in the two lenders’ contract rate offers, carried through the stress test.
The solution
A BC submortgage broker treated the insured-vs-uninsured question as the first thing to confirm, not an afterthought to check once a rate had already been chosen.
First, confirmed insured status before quoting anything. The mortgage’s original insurer confirmation and premium history settled the question — this file could never qualify for the uninsured straight-switch exemption, regardless of how clean the switch itself was.
Second, ran the qualifying-rate math for every lender on the shelf, not just the first one to make an offer, since the whole file turns on a contract-rate gap of less than one point.
Third, read the 2026 stress-test working reference against this specific file before quoting a client anything, since a wrong assumption about which switches are exempt is an easy, avoidable error with a client already expecting one outcome.
The outcome
Placed with Lender B: switched at maturity, insured status carried forward unchanged, qualifying at 6.49% against a 4.49% contract rate. No purchase occurred, so no land transfer tax or default-insurance premium tax applied — the only cost at closing was standard discharge and registration paperwork through the new lender.
The client was walked through both rows of the qualifying-rate table so the reasoning, not just the outcome, was clear: the exemption they had read about is real, but it never applied to their own file.
What to take from this file
- 01Confirm insured-vs-uninsured status before assuming any exemption applies. OSFI’s November 2024 straight-switch exemption covers uninsured mortgages only — an insured switch still requires the minimum qualifying rate in full.
- 02A straight switch being simple does not mean it is exempt. No increase to loan amount or amortization satisfies the shape of the exemption, but not its scope, if the mortgage is insured.
- 03On a tight file, the contract-rate gap between lenders is the whole game. Less than one point of difference in the offered rate was the entire distance between a decline and an approval here.
- 04Set client expectations correctly before quoting. A client who has read about an exemption that does not apply to them needs that explained clearly, not discovered at decline.
- 05Shop every switch across multiple lenders, especially an insured one, where the qualifying rate amplifies even a small contract-rate gap.
Sources
Every regulatory figure in this file traces to one of these primary sources. Client details and anything that varies by lender are illustrative, as flagged below.
- ▸OSFI — Minimum qualifying rate for uninsured mortgages — the minimum qualifying rate — greater of contract rate + 2% or 5.25%.
- ▸OSFI — OSFI exempts uninsured mortgage straight switches from the prescribed MQR and implements portfolio LTI limits — MQR exemption for uninsured straight switches at renewal (from Nov 21, 2024).
- ▸CMHC — CMHC Reviews Underwriting Criteria — GDS 39% / TDS 44% maximums and the 600 credit-score floor for insured files.
- ▸Provincial/territorial mortgage-broker legislation fetched directly (bclaws.gov.bc.ca, legisquebec.gouv.qc.ca, fcaa.gov.sk.ca, web2.gov.mb.ca, nslegislature.ca, assembly.nl.ca) plus FCNB's own site for NB and CanLII's index for PE — see notes for per-province method — provincial mortgage regulators and licence titles.
Illustrative in this file — lender-specific, not rules:
- ▸5.29% and 4.49% contract rate offers — rates move daily; not quotes.
- ▸$410/mo property tax and $140/mo heat estimate — lender-standard estimates, not rules.
Authority & provenance
How this case file was built
We publish the origin, the verification method and the reviewer for every case file, so you can judge how far to trust it before you rely on it with a client.
Where it comes from
Derived from files handled by Treadstone’s fulfillment desk and from scenarios contributed by partner brokerages. Names, employers, exact amounts and dates are changed so no client or file is identifiable.
Provenance: Composite — a pattern seen repeatedly on fulfilled files, not a single transaction.
What is verified
Every regulatory figure traces to a primary source listed above and was checked against it on the date shown. The arithmetic is recomputed by machine on every rebuild.
Anything that varies by lender is labelled illustrative rather than stated as a rule.
Who reviewed it
Reviewed for Canadian regulatory accuracy before publication, and re-checked whenever a cited rule changes.
Reviewed by: Nicholas Parson, Treadstone Associates — reviews every case file before publication.
This case file is professional reference material for licensed mortgage professionals. It is not advice to a borrower, and it is not a lender commitment. Insurer rules, qualifying rates and provincial taxes change — confirm the current position with the insurer, regulator or lender before you rely on any figure here in a live file.