Brokers often treat the credit score as the whole story — clear a number, clear the file. Underwriters read the bureau differently: the score is one gate among several, and the tradelines underneath it — what's open, what's owed, what's past due, and whether every debt on it matches what the application declared — usually matter more to the outcome than the three-digit number at the top.
This guide walks the bureau in the order an underwriter actually reads it: what gets checked first, what the published score minimum really means, how tradelines and utilization get weighed, how disputes and stale items get treated, and the specific mismatch — undisclosed debt — that changes a file's ratios more than any other single item on the report.
What underwriters check first on a credit bureau
The typical order is: does the score clear the applicable threshold; is there any active delinquency or collection; do the open tradelines and their balances match what the application declared; and has there been a recent flurry of credit inquiries suggesting new debt is forming outside the application. Each step can stop the file cold on its own, which is why reading them in order — rather than jumping straight to the score — catches problems earlier.
Step 1. Score context: what the published minimum actually means
CMHC's published minimum requires at least one borrower or guarantor to have a credit score of 600 for insured deals. That number is a floor, not a target — many individual lenders set their own, often higher, internal minimums on top of it, and clearing 600 doesn't mean every other item on the bureau is automatically acceptable.
The framing to use with clients: a passing score clears one gate. It says nothing yet about utilization, delinquency history, or whether every debt on the bureau matches the application — all of which still get reviewed independently.
Step 2. Tradelines, utilization, and history depth
- →Number and type of active tradelines — a healthy mix (credit card, line of credit, perhaps a car loan) reads better than a single thin file with one account.
- →Utilization ratio — balance relative to available limit on revolving accounts; consistently high utilization is read as a sign of financial strain even alongside an acceptable score.
- →Length of credit history — a longer, well-managed history generally reads more favourably than a short one, even at an identical score.
- →Recent hard inquiries — a cluster of recent inquiries can suggest new debt is being sought elsewhere, which matters directly to TDS if that debt isn't yet on the application.
Step 3. Disputes, stale items, and collections
A disputed item can still appear on a bureau report while the dispute is unresolved, and lenders tend to treat an open, unresolved dispute cautiously rather than simply ignoring it. How long negative information stays visible varies by item type — a useful starting reference is Equifax Canada's guide to how long information stays on a credit report. A collection account, even a small one, is worth resolving or clearly documenting before submission rather than leaving it for the underwriter to raise as a condition.
Step 4. The undisclosed-debt mismatch that kills TDS
This is the single most common credit-bureau surprise in mortgage underwriting: a line of credit, car loan, or other obligation shows up on the bureau but was never declared on the application. Because TDS is calculated from declared debts, an undisclosed obligation can swing the ratio enough to flip an approval into a decline — and it almost always surfaces after the bureau has already been pulled, which is exactly why cross-checking every tradeline against every declared debt, line by line, belongs in every file review before submission.
Coaching clients before you pull their credit
A short conversation before the credit pull prevents most surprises: ask the client to avoid applying for new credit anywhere else during the mortgage process, since each hard inquiry and any resulting new debt shows up on the bureau; ask them not to close older accounts, since that can shorten average history length; and ask them directly whether any debt exists that they haven't already mentioned, framed as helping the file move faster rather than as a test.
Reading a bureau this thoroughly on every file is exactly the kind of structured, repeatable review Treadstone's AI underwriting is being built to run instantly, currently in early access with an email waitlist. For a human fulfillment team running this review on files today, see Treadstone's fulfillment services, and pair this guide with the Pre-Underwriting File Review Checklist for the full pre-submission pass.