What Mortgage Underwriters
Actually Look For
I spent years reviewing mortgage files from the other side of the desk as a Senior Specialty Underwriter. What I learned about why loans get approved, declined, or stuck in conditions is what I use every day to structure applications for my clients. This is the inside view.
Why Brokers Who Have Never Underwritten a File Miss Things
Most loan officers learn the guidelines from a training manual. I learned them from reviewing what actually happened when files didn't meet them. That's a different education. When you have declined hundreds of files and approved thousands, you understand not just what the rule says, but what the rule is trying to prevent — and where there is legitimate flexibility versus where there is none.
The practical effect: when I put together a pre-approval, I'm looking at the file the way an underwriter will. Not the way a sales rep would. The goal is to have zero surprises between pre-approval and clear-to-close. That only happens if someone who has read those files gets to the problems first.
The Four Things Underwriters Actually Evaluate
Mortgage underwriting comes down to four factors. Every condition, every question, every documentation request traces back to one of these. Understanding them tells you why you were asked for something.
Income: Can You Repay This Loan?
The question isn't how much you make — it's how much of what you make the guidelines will allow us to count, and for how long. Base W-2 income is straightforward. Overtime and bonus income require a 2-year history and an expectation of continuance. Self-employment income is the hardest: we use the 2-year average from your tax returns, which means your deductions reduce your qualifying income in exactly the same proportion they reduce your taxable income. The business owner who writes off everything pays less in taxes and qualifies for less mortgage. That's the trade-off, and it's not a bureaucratic inconvenience — it's the system working as designed. Bank statement programs exist for borrowers whose tax returns misrepresent their actual cash flow, but they price differently.
Credit: What Does Your History Tell Us?
Underwriters don't just look at your credit score — they look at the story behind it. A 640 score from someone who had a medical event 3 years ago and has been perfect since tells a very different story than a 640 score from someone with 8 late payments in the last 2 years. Automated underwriting systems (AUS) read the pattern, not just the number. What I look for: the most recent 12 months of payment history, any open collections or charge-offs (some programs require payoff; others don't), bankruptcy discharge dates, and whether any derogatory marks are isolated events or part of a pattern. Isolated events with re-established credit can often be explained. Patterns can't.
Assets: Where Is Your Down Payment Coming From?
The question isn't just whether you have enough money — it's whether the money is yours, sourced, and documented. Down payment funds that can't be traced create questions about undisclosed debt (if you borrowed the down payment, your DTI is understated). Large deposits in your bank statements that appear within 60 days of application require sourcing. Gifts require a gift letter and documentation of the donor's ability to give. The 2-month bank statement requirement exists precisely to capture this window. One thing most borrowers don't know: reserve requirements. Some programs require 2, 3, or even 6 months of housing payment reserves after closing. Having exactly enough for the down payment and nothing left over can be a problem.
Property: Is the Collateral Worth What We're Lending?
The loan is secured by the property. If you default, the lender needs to be able to recover their money. This is why appraisals exist, why condition standards matter for FHA and VA, and why lenders impose LTV limits. From an underwriting perspective, the property review catches: appraisals that come in below contract price (which changes the loan amount and potentially the program), FHA/VA minimum property requirements that trigger repair conditions, and marketability issues in properties that are unusual, remote, or in poor condition. The deal that fails appraisal is usually a deal where no one ran the property risk before going under contract.
What an Automated Underwriting System (AUS) Actually Does
When you apply for a conventional loan, your file goes through Desktop Underwriter (Fannie Mae) or Loan Product Advisor (Freddie Mac). For FHA, it goes through TOTAL. These systems take your credit, income, assets, and property data and issue a finding — Approve, Refer, or Caution — along with specific conditions.
An "Approve/Eligible" finding is not approval. It's the system's statistical assessment that a loan with these characteristics has historically performed. A human underwriter still reviews the file, verifies the inputs, and issues conditions. But an Approve finding dramatically reduces the documentation burden — the underwriter can rely on the AUS findings and doesn't need to document every compensating factor manually.
A "Refer" finding means the system couldn't approve automatically and a human underwriter must evaluate every factor manually. Refer files are approvable — they just require more documentation and take longer. The triggers: credit score below the AUS floor, DTI above the standard maximum, thin credit history, or certain income types that AUS doesn't evaluate well (recent self-employment, income from boarders, etc.).
The Five Things That Slow Down or Kill Files in Underwriting
Income Documentation Gaps
Missing W-2s, missing pages of tax returns, or tax returns that don't match what was entered in the application. The most common: the self-employed borrower whose Schedule C shows losses in one year. A loss year averages the income down across 24 months — or eliminates the income entirely if the loss is large enough. This is discovered in underwriting, not at application, when the loan officer doesn't review the returns carefully upfront.
Undisclosed Debt
Credit pulled a second time before closing often reveals new debt opened after application — a new car loan, a credit card, or a store card opened to get a discount. New debt changes DTI. In some cases it pushes the file from approve to refer, or from qualified to ineligible. Never open new credit from application to closing without talking to your loan officer first.
Unsourced Funds
Large deposits within the 60-day statement window that the borrower can't document. Cash deposits are the worst case — there's no paper trail to source them. If you are selling an asset to fund your down payment, the sale needs to be documented. If family is giving you money, the gift letter process needs to be completed. If you received a cash bonus, the paycheck stub is the source document. Waiting until underwriting to deal with this adds 5-10 days to every deal.
Employment Gaps or Job Changes
A job change shortly before application isn't automatically a problem — changing employers in the same field at the same or higher income level is generally fine. A field change, a move from W-2 to self-employment, or a gap without explanation requires documentation. Underwriters need to determine that income is stable and likely to continue. A recent gap without a return to employment or a solid explanation creates uncertainty about continuance.
Property Condition Issues
FHA and VA have minimum property requirements that conventional doesn't. Peeling paint (FHA/VA lead paint concern on pre-1978 homes), missing handrails, broken windows, exposed wiring, roofs with limited remaining life — these are items that appraisers are required to call out. When they are called out, the lender requires repair before funding. In a seller's market, asking for repairs can cost you the deal. Knowing in advance which programs allow which conditions — and whether an as-is conventional appraisal is the right call — is something to discuss before you make your offer.
What Compensating Factors Actually Do
When a file has a risk factor — high DTI, lower credit score, limited credit history — compensating factors can allow the loan to proceed that might otherwise be declined. These are documented strengths that offset the weakness.
| Risk Factor | Compensating Factors That Help |
|---|---|
| High DTI (above 43%) | 12+ months reserves, perfect payment history, low LTV, significant cash savings |
| Low credit score (580-619 FHA) | Low DTI, large down payment, no derogatory marks in 12 months |
| Short employment history | Same field as prior employer, income increase, relevant education |
| Self-employment less than 2 years | Prior employment in same industry, strong income trend, business in operation |
| Thin credit (few tradelines) | 12+ months of timely rent payments, utility payment history, authorized user history |
| Large unsourced deposit | Consistent income deposits, documented overtime or bonus, bill of sale for sold asset |
What I Look For When I Review a File — Before an Underwriter Sees It
When a client comes to me for pre-approval, I run a mental version of what the underwriter will run. I'm looking for:
- →Does the income on the application match what the returns will actually produce when calculated per guidelines?
- →Is there any month in the last 24 where the bank statements show a large deposit that will need sourcing?
- →Are all credit accounts reflected on the application, including anything recently opened?
- →Is there a gap in the employment history that needs an explanation letter ready before the file goes to underwriting?
- →Does the property type match the program — is this a condo that needs a project approval, a 2-4 unit that needs rental income analysis, a rural property that needs a USDA eligibility check?
- →Are the reserves adequate for the program and the borrower's risk profile?
Catching these before submission is the difference between a 21-day close and a 45-day scramble. And for complex files — self-employed income, recently divorced borrowers, recent job changes, investors — it can be the difference between getting to the closing table and not.
The mortgage industry has a problem: most loan officers are salespeople who learn the guidelines from a manual but have never sat in an underwriter's chair. They know how to take an application. They don't always know how to build one.
When I was underwriting, the files that cleared conditions quickly were the ones where the loan officer had done the work upfront. Clean income calculations. Sourced deposits. Explanation letters pre-written. The files that sat in conditions for weeks were the ones where problems that should have been caught at application were discovered by the underwriter instead.
I build files the way I would want to receive them. That's not a sales pitch — it's just what happens when the person taking your application understands what happens to it afterward. If you have a file that another lender told you was complicated or borderline, tell me about it. There's a good chance I've seen something like it before.
Underwriting Questions Answered
What is the single most common reason mortgage files get denied?
How do underwriters actually calculate income for a mortgage?
What does 'layers of risk' mean in underwriting?
What is a mortgage overlay and how does it affect approval?
How do underwriters look at large bank deposits?
What is the difference between an approval, a conditional approval, and a denial?
Mortgage Underwriting and Approval Resources
Want Dan to Review Your File Before You Apply?
A pre-approval from a former underwriter is different from a pre-approval from a salesperson. Call (661) 342-9381 or apply online.