Underwriting
Underwriting is the decision to lend. Everything before it — application, pre-approval, document gathering — is preparation for it, and everything after it is administration.
What is being assessed#
The traditional framing is four questions, and it still describes the process accurately.
Capacity. Can the borrower afford the payment? This is where debt-to-income lives, along with employment stability and the reliability of the income.
Credit. Has the borrower repaid obligations before? Score matters, but so does the pattern — a single medical collection reads differently from a history of late mortgage payments.
Capital. What does the borrower have available? Down payment, reserves after closing, and where the money came from. Large recent deposits attract questions, because undisclosed borrowed funds change the picture.
Collateral. Is the property worth enough, and is it acceptable security? The appraisal answers the first part; condition, property type and marketability answer the second.
Automated first, human second#
Most residential applications run through an automated underwriting system that returns a recommendation in minutes.
That recommendation is not the decision. A human underwriter reviews the file against it, and files that fall outside the automated parameters go to manual underwriting, which is slower and considers circumstances an algorithm cannot.
Conditions#
Approval almost always arrives conditional.
The conditions are specific documents or explanations required before closing — an updated pay stub, a letter explaining a deposit, evidence that a debt shown on credit has actually been paid, a repair completed before funding.
Clearing them is where most of the elapsed time in a mortgage goes, and it is where borrowers have the most control. Conditions answered the same day compress a timeline that otherwise drifts.
What breaks an approved file#
Approvals unravel, and the causes are consistent.
Taking on new debt during the process — financing furniture, opening a card, buying a car — moves the DTI the loan was approved against. Changing jobs changes the income analysis. A large deposit with no traceable source raises a question that must be answered. An appraisal below the contract price changes the loan-to-value and can require more cash at closing.
The general rule underwriters would give if asked: between application and closing, change nothing about your finances that you do not have to.
Manual underwriting#
Not every file fits an automated model, and a referral to manual underwriting is not a rejection.
It is how lenders handle borrowers with thin credit files, non-traditional income, recent but explained derogatory events, or documentation that requires judgement. A human reads the whole picture rather than scoring the parts.
Manual underwriting is slower and asks for more — often twelve months of cancelled cheques for rent, or letters explaining specific events, or reserves the automated path would not have required.
For self-employed borrowers and for anyone rebuilding after a hard few years, it is frequently the route that works when the algorithm says no. Knowing it exists is worth something, because a borrower told "the system declined it" may assume the answer is final when it is not.