Treadstone Associates
Case File № 128 · Self-Employed Income

The side business a lender wouldn't touch

a steelworker's combined-income file in Sault Ste. Marie

A steelworker's T4 income alone wasn't quite enough for the purchase he wanted, and a lender's self-employed overlay refused to count his small side welding business at all. Adding it on its own two-year average brought TDS from 48.8% to 42.4%.

OntarioInsured · 90% LTVFiled August 7, 20266 min read
48.8%

TDS on the T4 alone — declined

42.4%

TDS with the side business added — approved

39/44

CMHC’s maximum GDS / TDS for insured files

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 steelworker in Sault Ste. Marie, with a stable T4 job at a local mill, also runs a small welding and repair side business on evenings and weekends, reported on its own T2125. His first lender's self-employed overlay treated any sole-proprietorship on the file the same way — and excluded the side business entirely.

Borrower

Steelworker, T4-salaried

Plus a side welding/repair sole proprietorship

T4 income

$76,000 / year

$6,333 per month, multi-year tenure

Side business T2125, Year 1

$9,000

Evenings/weekends, first full year

Side business T2125, Year 2

$14,000

Second year, growing client base

New purchase

$345,000 detached, Sault Ste. Marie

Property tax $300/mo; heat estimate $130/mo

Down payment

$34,500 — 10%

Under 20%, so the file must be default-insured

The side business's two T2125 years:

Side business T2125 net incomeAmount
Year 1$9,000
Year 2$14,000
Two-year average$11,500/yr — $958/mo
№ 02

The problem

The bank's policy for any file touching self-employment income was blanket, not proportional: it required two full years of standalone documentation before counting a dollar, and it applied that rule to the whole file rather than scaling it to how small the side business actually was next to a stable primary T4 income. With the side income at zero, the file came up short.

The T4-only arithmetic

  • Income used: $6,333/mo (T4 only, side business excluded)
  • Liabilities: mortgage payment at the qualifying rate + property tax + heat + car loan
  • TDS: 48.8% — against CMHC’s 44% maximum. Declined.

The T4 income on its own was genuinely strong and stable — the file wasn't hard because of anything wrong with the primary employment. It was hard because a lender's all-or-nothing self-employed policy meant a few hundred dollars a month of side income, fully documented on two T2125s, contributed nothing to qualifying.

№ 03

The numbers

At 10% down this is an insured purchase, so CMHC's maximums — GDS 39%, TDS 44% — are hard caps.

Structuring the insured loanAmount
Purchase price$345,000
Down payment (10%)−$34,500
Base mortgage (90% LTV)$310,500
CMHC premium — 3.10% in the 85.01–90% LTV band, capitalized+$9,626
Total insured mortgage$320,126
Rate & paymentsFigure
Contract rate — 5-year fixed (illustrative, not a quote)4.89%
Minimum qualifying rate — greater of contract + 2% and 5.25%6.89%
Monthly P&I at the qualifying rate — the ratios run on this$2,221
Monthly P&I at the contract rate — what they actually pay$1,842

T4 alone vs. T4 plus the averaged side business

The T4 income counts in full from day one, backed by a letter of employment; the side business is added separately, on its own standard two-year average.

Income treatmentT4 aloneT4 + side business average
Income, monthly$6,333$7,291
GDS41.9%36.4%
TDS vs. the 44% cap48.8%  ✗42.4%  ✓

Adding the side business's modest $958/mo average is enough on its own to move TDS from a declined 48.8% to an approved 42.4%.

№ 04

The solution

An FSRA-licensed Ontario mortgage agent placed the file with a lender whose combined-income policy scales to the size of the side business rather than applying the same bar it would to a borrower who is self-employed full time.

First, separated the two income sources on their own terms. The T4 job needed only the usual employment documentation; the side business needed its own two-year average, run the same way it would be for any sole proprietorship. At $320,126, the insured mortgage itself was modest against the average new mortgage amount in Canada, which made the side business's contribution proportionally larger to the outcome.

Second, matched the file to that lender's published combined-employment policy rather than the first bank's blanket self-employed overlay, which didn't distinguish a primary T4 with a small side business from a borrower who is fully self-employed.

Third, packaged full documentation for both income sources so there was no ambiguity about which rules applied to which income.

Letter of employment and recent pay stubs for the T4 job
Two years of T1 Generals with the side business's T2125
Two years of Notices of Assessment
Business licence/registration for the side business
90-day history of the $34,500 down payment

With both income sources documented on their own terms, the insurer's approval followed the lender's.

№ 05

The outcome & the closing math

Approved and funded: insured at 90% LTV, 25-year amortization, 5-year fixed term. The side business kept running unchanged — it never had to become the borrower's main income to matter to the file.

Cash due at closing (beyond the down payment)Amount
Ontario land transfer tax on $345,000 — marginal brackets; no first-time-buyer refund for a repeat buyer$3,650
Ontario RST on the insurance premium — 8% × $9,626$770
Legal fees, title insurance & adjustmentsvaries

The lender also required evidence of funds to cover closing costs on top of the $34,500 down payment, which the same 90-day statements demonstrated.

№ 06

What to take from this file

  • 01A blanket self-employed policy can penalize a borrower whose side income is genuinely small. Look for a lender whose combined-income treatment scales to the proportion of self-employment in the file.
  • 02A stable T4 job counts in full from day one. Only the self-employed portion of a combined-income file needs the two-year average.
  • 03Even a modest side income can be the difference on a tight file. $958 a month moved this file from declined to approved.
  • 04The ratios run at the qualifying rate, not the contract rate. This file qualifies at 6.89% and pays at 4.89% — a $379-a-month gap.
  • 05Budget the closing cash separately from the down payment. Land transfer tax and RST on the premium added $4,420 in cash before legal fees.

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:

  • 4.89% contract rate — rates move daily; not a quote.
  • two-year averaging convention for the side business — each lender sets its own policy for combined employment plus self-employment files.

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.