What Happens in Mortgage Underwriting?

The question: What happens in mortgage underwriting, and what does an underwriter look for before approving or denying a home loan?

The short answer: Underwriting is the lender’s check that you, your income and the property meet the rules of the loan program you applied for. An automated system scores the file first, and then a human underwriter verifies the documents and makes the decision. Many files come back approved with conditions, which means the lender needs a few more papers before it issues the “clear to close.” Denials usually trace to a few common problems: debt that is too high for your income, credit history, an appraisal or property issue, or money the lender cannot verify.

What is mortgage underwriting and who does it?

Mortgage underwriting is the step where the lender decides whether your loan meets the program’s standards. Fannie Mae’s Selling Guide describes it as a review of your equity investment, credit history, reserves and “reliable and recurring income,” along with how those risk factors add up. The underwriter also reviews the appraisal, because the home secures the loan.

In mortgage underwriting, two parties do the work. First, an automated underwriting system (AUS) scores the application against the program’s risk model. Next, a human underwriter checks that the documents support every number the system used. If a pay stub, bank statement or credit report does not match, the underwriter corrects the data and runs the file again.

What results can underwriting return?

The automated finding is a recommendation, and the lender still makes the final decision. VA’s Lender’s Handbook says it plainly: the automated systems “do not approve or disapprove loans.” After the review, a file usually lands in one of these spots:

• Approved with conditions. The lender will make the loan once you supply specific items, such as a missing bank statement page or a letter of explanation.
• Suspended. The underwriter cannot reach a decision yet because something major is missing or unclear. The file sits until you resolve it.
• Denied. The loan does not meet the program’s rules or the lender’s own standards.
• Clear to close. Every condition is met, so the lender can prepare final documents and schedule closing.

Labels vary by lender. A conditional approval means the underwriter will approve the loan once you meet the listed conditions.

What do mortgage underwriters check?

Mortgage underwriting covers credit, capacity, capital and collateral, sometimes called the four C’s. Freddie Mac’s Guide lists three: credit reputation, capacity, and collateral that is “adequate for the transaction.” No single factor decides the file. Fannie Mae’s guide notes that its system “identifies low-risk factors that can offset high-risk factors.”

Credit: your payment history and score

The lender orders a merged credit report from the three bureaus (Fannie Mae requires this for conventional loans). The underwriter then reviews payment history, balances, recent inquiries and any collections, bankruptcy or foreclosure. Fannie Mae removed its 620 minimum credit score for new Desktop Underwriter loan casefiles on 2025-11-16, although lenders can still set a higher minimum of their own.

Since 2026-09-09, Fannie Mae and Freddie Mac let all approved lenders use VantageScore 4.0 in place of a classic FICO score in automated underwriting. Fannie Mae extended that choice to manual underwriting on 2026-11-04. It requires the same score model for every borrower on the loan.

Capacity: income, employment and DTI

Capacity means your ability to make the payment. The underwriter confirms your income with pay stubs, W-2s or tax returns, and then calculates your debt-to-income ratio (DTI). DTI is your monthly debt payments, including the new housing payment, divided by your gross monthly income. For Fannie Mae loans, the cap is 50% through Desktop Underwriter and 36% for manual underwriting, or up to 45% with enough credit score and reserves.

Bonus, overtime and self-employment income usually need a history before they count, as our guide to what lenders count as mortgage income explains. Student loans usually count toward DTI even when payments are deferred, though VA lets a lender leave out a loan deferred at least 12 months past closing. See how lenders calculate student loan payments.

Capital: down payment, reserves and deposits

The underwriter verifies that you have the down payment and closing costs, plus any reserves the program requires. Under Fannie Mae and FHA rules, a single deposit of more than 50% of your monthly income is a large deposit. FHA requires documentation of each one. Fannie Mae requires it when the money is needed for your down payment, closing costs or reserves, except for deposits whose source is clear on the statement, such as payroll. Our article on large deposits on a mortgage application explains what paperwork works.

Gift money needs a signed gift letter from the donor. In addition, Fannie Mae requires the lender to verify the gift funds, either in the donor’s account or after the transfer to yours.

Collateral: the appraisal and the property

The home secures the loan, so the underwriter reviews the appraisal for value and condition. On a purchase, Fannie Mae figures the loan-to-value ratio from the lower of the sales price or the appraised value. A title search also has to show that the seller can transfer clean ownership. See five property appraisal problems that can risk approval.

Document checklist for mortgage underwriting

Lists vary by lender, but most mortgage underwriting files need the documents below.

How does automated mortgage underwriting work?

Each loan program has its own automated system or scorecard. The lender enters your application and credit data, and the system returns a finding plus a list of documents the lender must collect.

An “eligible” or “accept” finding means the file fits the program’s risk model, provided the data proves accurate. It does not mean approval. HUD’s Handbook 4000.1 says a lender “may not accept or deny an FHA-insured Mortgage based solely on” the TOTAL score.

When does a loan go to manual underwriting?

A “refer” or “caution” result sends the loan to manual underwriting, where a person reviews the full file against the program’s written rules. The loan can still be approved. Fannie Mae’s Selling Guide tells lenders to check the data first, fix errors and resubmit. If the file still gets Refer with Caution, the lender may manually underwrite it when the product allows that.

FHA also forces some files with an Accept into manual underwriting. According to HUD Handbook 4000.1, section II.A.4.a.v, triggers include:

• $1,000 or more in disputed derogatory credit accounts
• A bankruptcy discharge within two years of the FHA case number date
• A foreclosure, short sale or deed-in-lieu within three years of the case number date
• Information the scorecard cannot evaluate
• Business income that fell more than 20% over the analysis period

Manual underwriting usually brings tighter limits. For example, Fannie Mae’s DTI cap drops from 50% in DU to 36%, or 45% with the required credit score and reserves. Also, lenders can choose whether to offer manual underwriting.

What are the steps in the mortgage underwriting process?

The underwriting process starts once you have a signed purchase contract and a full application. If you got a mortgage pre-approval letter, part of this work is already done. Even so, the underwriter will update documents that have aged since then.

1. Submission. Your loan processor gathers your documents, orders the appraisal and title work, and sends the file to underwriting.
2. Automated finding and initial review. The system scores the file. Then the underwriter checks each figure against your documents.
3. Conditional approval. The underwriter issues a list of conditions. Many lenders sort them as “prior to docs” (needed before closing documents are drawn) and “prior to funding” (needed before the money is released).
4. Clearing conditions. You send what the list asks for. A letter of explanation is a common condition, for example for a credit inquiry or a gap in employment.
5. Final verification. Before closing, the lender confirms your job again. For wage earners, Fannie Mae requires that verbal check no more than 10 business days before the note date (120 days for self-employed borrowers). Fannie Mae also expects lenders to run prefunding checks for new debt or reduced income, so a credit refresh before closing is common.
6. Clear to close. Once every condition is met, the lender issues the clear to close and prepares the Closing Disclosure. Federal rules require you to receive that disclosure at least three business days before closing.

Fannie Mae also caps how old credit documents can be. They must be no more than four months old on the note date, so a long closing can mean new statements.

Why do loans get denied in mortgage underwriting?

Most home purchase applications that reach a decision are approved, and denials cluster around a few reasons.

How often do underwriters deny loans?

No public data isolates denials that happen after underwriting starts. The closest figure comes from Home Mortgage Disclosure Act (HMDA) data, which counts denials at any stage. From the 2025 HMDA data published by the FFIEC, we calculated denial rates for first-lien home purchase applications on owner-occupied, site-built homes. Like the CFPB in its HMDA reports, we left out withdrawn and incomplete applications.

Among denied purchase applications in 2025, lenders listed debt-to-income ratio as a reason in about 43%. Credit history followed at about 19%, and collateral at about 16%. A lender can list up to four reasons for each denial.

The most common reasons for a denial

• DTI too high. HMDA data lists this reason most often. It can surface late if the underwriter counts less income than your pre-approval did, or finds a debt you did not list.
• New debt or a credit score drop. A new car loan, store card or large card balance can push DTI over the limit. Fannie Mae requires a re-underwrite when new debt raises DTI beyond set tolerances. If your score slipped, read why credit scores suddenly decline.
• A job change or lost income. Switching employers, moving to commission pay, or going self-employed can change how the lender counts income. See what to do about a job change before closing.
• Self-employed income that is too short or too low. Fannie Mae generally wants a two-year history, though 12 months on a recent return can work with other support. The lender analyzes your tax returns to work out how much income the business can pay you, so large write-offs can lower the income that counts.
• Money the lender cannot source. Cash deposits, transfers from undisclosed accounts, or a gift without a paper trail can stall a file. List every account, even ones you do not plan to use.
• A low appraisal. If the home appraises below the price, the loan amount drops or you need more cash. See what to do when an appraisal comes back low.
• Title or property problems. Unpaid liens, ownership disputes, or a condition the program does not allow can delay or stop closing.

Example: how one new loan changes DTI

Say a buyer earns $10,000 a month before taxes. Their new housing payment is $3,000, covering principal, interest, property taxes, insurance and mortgage insurance. They also owe $1,000 a month on other debts, which puts DTI at 40%. If they finance a car for $600 a month before closing, DTI rises to 46%. That figure tops Fannie Mae’s 45% manual underwriting cap. It is still under DU’s 50% limit, but the lender must re-run the file, and the result can change.

If the lender does deny the loan, federal rules require notice of the decision within 30 days of a completed application. For the steps after that, read what to do after a mortgage denial.

Should you be worried about mortgage underwriting?

For most buyers, no. If your pre-approval was based on verified documents and nothing has changed, underwriting mostly confirms what the lender already saw. Worry makes sense only when something changed after you applied: new debt, a new job, a big deposit, or a late payment.

Why is mortgage underwriting taking so long?

We found no standard underwriting timeline in Fannie Mae, Freddie Mac, FHA, VA or USDA guidance, so treat any day count as one lender’s estimate. Delays usually come from three sources: missing documents, an appraisal or title report that has not come back, and a file that needs a manual underwrite. Your purchase contract sets the closing date, and the lender works backward from it, since the Closing Disclosure must reach you three business days before closing.

What not to do while your loan is in underwriting

• Hold off on new credit, financed furniture and co-signing.
• Keep your job and pay structure, or tell your loan officer before anything changes.
• Leave large sums where they are, and skip cash deposits you cannot document.
• Pay every bill on time, including utilities that could go to collections.
• Answer each condition request, the same day if you can, with all pages of every statement.

For more ways to keep the file moving, see seven ways to speed up your loan closing and the pre-approval mistakes that often cause late trouble.

FAQ

How long does mortgage underwriting take?

A simple file with an automated approval can clear quickly, while a manual underwrite or a missing appraisal adds time. Ask your loan officer for their current turn time.

Does underwriting mean I’m approved?

No. Underwriting is the review itself, and it can end in approval, a suspension or a denial. You are approved once the underwriter signs off, and you are ready to close only when the lender issues a clear to close.

What is a conditional approval?

It means the underwriter will approve the loan once you meet a list of specific requirements. Typical conditions include an updated pay stub, a missing statement page or a letter of explanation. Conditions are routine.

How often do underwriters deny loans?

In 2025, lenders denied 8.5% of first-lien, owner-occupied home purchase applications that reached a decision, based on our calculation from FFIEC HMDA data. That figure covers denials at every stage, so no public number shows how many files fail after underwriting begins. Refinance applications were denied more often, at 25.8%.

Can underwriting be denied after clear to close?

Yes. Lenders verify employment again shortly before closing and may check for new debt. If your income drops or your debts rise enough, the loan has to be re-underwritten, and it can fail.

Do underwriters check bank statements?

Yes. Underwriters review recent statements for every account you list to confirm your down payment, closing costs and reserves. They also look for large deposits and transfers from accounts you did not list.

Should I be worried about underwriting?

Usually not, if your finances have stayed the same since pre-approval. The risk comes from changes, such as new credit, a job switch or unexplained deposits.

What to do while your loan is in mortgage underwriting

Treat the weeks your loan spends in mortgage underwriting as a freeze on your finances. Keep your job, debts and accounts as they were when you applied, and send each requested document the day you get the request. If something has already changed, tell your loan officer now.

If you are still choosing a lender, compare a few offers and ask each one about its turn time and whether it offers manual underwriting.