Every mortgage application starts with a number the borrower believes is their income. Until that number is supported by paper, it is a claim, not income — and the whole discipline of income documentation is the process of turning a claim into something an underwriter can rely on.
The distinction matters because the required proof is not the same for every income type. A salaried employee's claim is easy to support. A borrower on maternity leave, a contractor between placements, or a self-employed tradesperson are all making the same kind of claim in principle, but each needs a different kind of paper trail to back it up — which is exactly what this course works through, income type by income type.
Not all proof is equal. Broadly, underwriters trust documents in this order: government or CRA-issued documents first (a Notice of Assessment, a T4, a T4A), employer-issued documents second (a letter of employment, a pay stub), and the applicant's own statement last. A government document is trusted most because a third party — the Canada Revenue Agency, or Service Canada — produced it independently of the borrower, based on a return that was actually filed. It is harder to falsify and carries a paper trail of its own.
OSFI's Guideline B-20, which sets the underwriting expectations federally regulated lenders must meet, puts this directly: "Income is a key factor in assessing the capacity to repay a mortgage loan, and verification of income helps to detect and deter fraud and misrepresentation." That single sentence is why a letter alone, without a pay stub or a Notice of Assessment behind it, rarely satisfies a file on its own.
Tenure means more than "years with this employer." It means how long the specific pay structure being claimed has actually existed — a new salary after a promotion, a new bonus plan, a first year of guaranteed hourly hours, a business that opened eighteen months ago. A borrower can have ten years of work history and still have almost no tenure in the income line they're trying to qualify on.
Lenders differ on exactly how long a probationary period or a new pay structure needs to run before it's fully trusted — this course teaches the underlying question, not one lender's specific cutoff, because that cutoff moves and varies by program. The question underneath is always the same: is there enough of a track record here to believe this income continues past closing day?
The next nine modules work through the income types a broker meets most often: salaried employment, hourly work, bonus/overtime/commission, contract employment, part-time and multiple jobs, maternity and parental leave, income from a family business, pension and investment income, and foreign income. Each module closes with the specific document set that makes that income type usable.
Two related topics live elsewhere on purpose, so this course doesn't duplicate them: the full mechanics of self-employed and incorporated income — T1 vs T2, add-backs, dividends vs salary — belong to Course 03, Self-Employed & Incorporated Borrowers, and rental or investment-property income belongs to Course 08, Rental & Investment Property Underwriting. Where this course brushes against either, it will point there rather than re-teach it.
A file includes a Notice of Assessment showing last year's income, and a current pay stub showing a higher year-to-date figure after a recent raise. What should the underwriter do with these two documents?
Neither document alone tells the whole story. The NOA is trustworthy but backward-looking — it can't see a raise that happened after the tax year ended. The pay stub is current but self-reported and covers only one pay period. Reading them together, supported by an employment letter confirming the new rate is permanent, is how a genuine increase gets documented. Relying on the pay stub alone is the most common mistake here, because a single strong pay period says nothing about whether the new rate is real and ongoing rather than a one-off bonus period.
