Treadstone Associates
Case File № 072 · Renewals & Switches

No stress test at renewal

an uninsured straight switch in Peterborough

An uninsured mortgage renewing as a straight switch between two federally regulated lenders would normally be tested at 6.79%. OSFI’s exemption for straight switches lets it qualify at the actual 4.79% contract-rate payment instead, provided the loan amount and amortization don’t increase.

OntarioUninsured · Straight switchFiled August 7, 20265 min read
6.79%

What a fresh stress test would have required

4.79%

The contract rate the file actually qualifies at, exemption applied

$593

Monthly qualifying-rate headroom the exemption avoids

Anonymized illustration. The borrowers, dollar figures, and rates in this file are an illustrative composite — no real client is identifiable, and any rate shown is illustrative, not a quote. The rules are real: every regulatory figure is cited to its source in the Sources section, and the math computes exactly as shown.

№ 01

The client

A borrower’s uninsured mortgage in Peterborough matured with a $520,000 balance and 22 years of amortization remaining, arriving in the middle of the heavier 2026 renewal wave. The new lender’s offer was materially better than a straight renewal with the maturing institution.

Existing mortgage

$520,000 balance, uninsured

22 years remaining amortization

Income

$9,500/mo combined

Car loan $380/mo

Switch structure

Same balance, no increase to amortization

No cash-out taken

New lender

Federally regulated institution

Contract rate 4.79%, 5-year fixed (illustrative)

№ 02

The problem

A straight switch between two federally regulated lenders is, in OSFI’s own language, still a new mortgage from the receiving lender’s point of view — which would normally mean testing it at the minimum qualifying rate, not the contract rate.

What a normal new-mortgage stress test would have required

  • Qualifying rate: greater of 4.79% + 2% and 5.25% = 6.79%
  • Payment used for underwriting: $3,769/mo
  • TDS at that payment: ($4,199 housing + $380) ÷ $9,500 = 48.2%

48.2% is a heavier debt-service load than the file needed to show, on a borrower whose income and property haven’t changed at all since the mortgage was first advanced.

№ 03

The numbers

Effective November 21, 2024, OSFI stopped requiring the minimum qualifying rate on an uninsured straight switch between two federally regulated lenders at renewal, provided the loan amount and remaining amortization don’t increase — exactly the shape of this file, and one reason renewal volume keeps climbing without a matching spike in stress-test declines.

The two ways this switch could have been testedAmount
Balance switched$520,000
Remaining amortization22 years
Contract rate offered4.79%
Minimum qualifying rate (if tested)6.79%
Renewal testPaymentHousing costsTDS
If tested at the qualifying rate$3,769$4,19948.2%
Exempt as a straight switch (actual contract rate)$3,176$3,60642.0%

The $593-a-month gap between $3,769 and $3,176 is the entire effect of the exemption: same balance, same amortization, same borrower, tested at a materially lower payment because the switch meets both of OSFI’s conditions — no increase in loan amount or remaining amortization, and federally regulated lender to federally regulated lender.

№ 04

The solution

An FSRA-licensed Ontario mortgage agent confirmed both conditions before submitting: the new balance would not exceed $520,000, the amortization would not extend past 22 years, and both the outgoing and incoming institutions are federally regulated. None of that changes the lender’s own underwriting — OSFI’s guidance is explicit that lenders must still assess the switch using sound B-20 principles — but it removes the prescribed stress-test rate from the file.

The submission notes documented the exemption basis directly — the same checklist our stress test calculation worksheet walks through — so the file did not need to justify a 48.2% TDS the borrower was never actually going to carry.

№ 05

The outcome

The switch completed at the 4.79% contract rate, tested at that same rate rather than 6.79%. The borrower’s actual monthly payment of $3,176 is what both qualified the file and what hits the account — there is no gap between the qualifying payment and the real one here, which is itself a feature of the exemption, not a coincidence.

OSFI has also signalled it will revisit whether a Superintendent-prescribed minimum qualifying rate is still needed on new uninsured originations once its loan-to-income limit framework is fully phased in — a direction to watch, not yet a further rule change.

№ 06

What to take from this file

  • 01The exemption has two conditions, both must hold. No increase in loan amount or remaining amortization, and federally regulated lender to federally regulated lender — check both before assuming a switch qualifies for the exemption.
  • 02Exempt from the rate test is not exempt from underwriting. OSFI still expects the receiving lender to apply sound B-20 judgment to income, credit and property — the exemption removes one specific rate hurdle, not the file review.
  • 03Document the exemption basis in the submission. Showing the balance and amortization didn’t increase, and that both institutions are federally regulated, avoids the file being tested at the higher rate by default.
  • 04The gap this avoids is real money. On this file it was $593 a month of qualifying-rate headroom the borrower never had to show.

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.

Illustrative in this file — lender-specific, not rules:

  • 4.79% switch contract rate — rates move daily; not a quote.
  • the TDS comparison — this file is uninsured, so there is no CMHC ratio ceiling — the numbers show the stress-test gap the exemption avoids, not a regulatory pass/fail line.

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.

First published 7 August 2026Rules last verified 7 August 2026Next scheduled review 7 February 2027

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.

Treadstone fulfillment

Files like this are daily work for our desk.

Document collection, ratio math under multiple treatments, lender placement notes, and submission-ready packaging — for Canadian mortgage brokers who would rather be in front of clients.