The most common first-time home buyer mistakes happen after preapproval, not before it. Taking on new debt, making a large purchase, changing jobs, letting multiple lenders pull your credit, missing a payment, or depositing unexplained cash into your bank account can all trigger a second look from underwriting.
Avoiding these moves between preapproval and closing is the single best way to keep your mortgage on track.
TL;DR
First-time buyers often assume that once they are preapproved, the loan is locked in. It is not. Lenders re-verify credit, income, and bank statements again before closing, and any financial change in between can raise a flag.
This article covers the specific moves that cause the most delays or denials and what to do instead so your file stays clean through closing. If you are already mid-process, a quick check-in with your loan officer before making any money moves is the safest habit to build.
Preapproval is a snapshot of your finances on the day it was pulled. Between that day and closing day, your lender is watching for anything that changes the picture. The sections below walk through the specific mistakes that cause the most damage and how to avoid each one.
Why Does Taking on New Debt Before Closing Put Your Mortgage at Risk?
New debt raises your debt-to-income ratio (DTI), which is the percentage of your monthly income already committed to debt payments. Lenders requalify your DTI right before closing, so a new car loan, personal loan, or store financing plan can push you over the threshold your loan program allows, even if you were approved weeks earlier.
This applies to any new credit account, not just large purchases. Financing furniture, appliances, or even a phone through a retailer’s payment plan counts as new debt in the lender’s eyes. If a purchase requires signing a credit agreement, treat it as off-limits until after closing.
The safest rule is simple: do not open, cosign, or add yourself to any new debt between preapproval and closing, no matter how small the payment seems.
“The biggest surprises we see in underwriting are not big financial decisions. They are small ones borrowers did not think to mention.”
— Charlie Cooper, President, Austin Capital Mortgage
Can a Large Purchase Really Delay or Derail Your Mortgage Approval?
Yes, a large purchase can delay or derail approval even when it is paid in cash rather than financed, because it reduces the reserves and verified assets your lender counted toward your down payment, closing costs, or required reserves. Underwriters look at your bank statements again close to closing, and a sudden drop in balance can trigger a request to explain where the money went.
Common examples include buying furniture in advance, paying a moving company a large deposit, or purchasing a vehicle outright. Any of these can leave your account short of what the lender verified at preapproval.
Hold off on large purchases, whether financed or paid in cash, until after your loan has funded and closing is complete.
Is It Safe to Change Jobs While Your Mortgage Is in Underwriting?
Changing jobs while your mortgage is in underwriting is one of the riskier moves a borrower can make, because lenders rely on employment and income history to confirm your ability to repay the loan. A new job, even with a pay increase, can require a new verification of employment, a probationary period, or additional documentation that was not part of your original file.
Some situations are more disruptive than others. Switching from salaried W-2 income to a 1099 or self-employed role is treated as a significant income change and often requires a longer history before the new income can be counted. Moving to a different employer in the same line of work with a similar pay structure is usually easier to document, but it still needs to be disclosed and verified before closing.
If a job change is unavoidable, tell your loan officer immediately so they can determine what documentation is needed and whether your closing timeline needs to adjust.
Does Shopping for Rates or Multiple Credit Inquiries Hurt Your Approval?
Rate shopping within a focused window, typically 14 to 45 days depending on the credit scoring model, is generally treated as a single inquiry for mortgage purposes and has minimal impact on your score. The bigger risk is credit inquiries from unrelated sources, such as applying for a store card, an auto loan, or a personal loan while your mortgage is in process.
Each new inquiry outside the mortgage shopping window can lower your credit score and may signal to the lender that you are taking on new obligations, which brings your file back under review. Lenders also re-pull credit shortly before closing specifically to check for new inquiries and new accounts.
Limit hard credit inquiries to mortgage rate shopping done in a short window, and avoid applying for any other type of credit until after closing.
Read more about FHA credit score requirements.
What Happens If You Miss a Payment During the Mortgage Process?
A missed payment during the mortgage process, even a small one, can lower your credit score and may require a written letter of explanation before your lender will move forward. Payment history is one of the most heavily weighted factors in your credit score, and a late payment reported during underwriting can be enough to change your qualifying terms or delay your closing date.
This is especially risky in the final 30 to 60 days before closing, when lenders re-check credit and account activity. A missed credit card, auto loan, or even a utility bill that reports to credit bureaus can surface at the worst possible time.
Set up autopay or calendar reminders for every recurring bill from the day you are preapproved through your closing date, and contact your lender right away if a payment is ever missed.
Why Do Unexplained Deposits or Moving Money Cause Underwriting Delays?
Unexplained deposits cause delays because lenders are required to verify the source of funds used for your down payment, closing costs, and reserves, and any deposit that does not match your documented income raises a compliance flag. This includes cash gifts, payments from friends or family, freelance income, or transfers between your own accounts that are not clearly documented.
Moving money between accounts close to closing can also cause problems, even when the money is entirely yours. Large transfers can look like new deposits to an underwriter reviewing a different account, and can require additional statements or explanation letters to trace.
Keep your funds in one account as early as possible in the process, avoid shifting money between accounts, and tell your loan officer in advance about any gift funds so the paperwork can be prepared before it is needed.
“If you would have to explain a deposit to a stranger, explain it to your loan officer first.”
— Charlie Cooper, President, Austin Capital Mortgage
Myth vs. Fact: First-Time Buyer Mortgage Mistakes
| Myth | Fact |
|---|---|
| Once you are preapproved, your loan is locked in. | Lenders re-verify credit, income, and assets again before closing, and changes in between can affect your approval. |
| A cash purchase cannot hurt your mortgage. | Large cash purchases can reduce verified reserves and assets your lender counted toward the loan. |
| A better job offer will only help your approval. | A job or income change, even a raise, can require new verification and may delay closing depending on the change. |
| Rate shopping always hurts your credit score. | Mortgage rate inquiries within a short shopping window are typically counted as one inquiry, not several. |
| Gift money does not need to be documented if it is a small amount. | Any deposit that does not match your documented income can require a source-of-funds explanation, regardless of size. |
What This Looks Like in Practice
A first-time buyer was several weeks into underwriting when a relative gave them five thousand dollars toward closing costs. They deposited the check without mentioning it to their loan officer, assuming a family gift would not raise questions.
When the lender reviewed updated bank statements before closing, the deposit did not match any documented income source, which triggered a request for a gift letter, proof of the relative’s ability to give the funds, and a paper trail showing the money left one account and landed in the other.
The documentation took several days to gather, which pushed the closing date back by about a week. The loan still closed, but the delay could have been avoided entirely. Any deposit that is not part of your regular, documented income should be flagged to your loan officer before it hits your account, not after.
“A gift can absolutely help with closing costs, but the paperwork has to happen before the money moves, not after.”
— Charlie Cooper, President, Austin Capital Mortgage
Your Next Steps
- Avoid opening, cosigning, or financing any new debt until after closing
- Hold off on large purchases, financed or in cash, until your loan has funded
- Tell your loan officer immediately about any planned job change
- Keep credit inquiries limited to mortgage rate shopping in a short window
- Set up autopay on every recurring bill through your closing date
- Flag any gift funds or unusual deposits with your loan officer before you deposit them
Learn more about first-time home buying.
Ready to move forward? A loan officer can review your full scenario and flag anything in your file that could cause a delay before it becomes a problem.
Talk to a Loan Officer Before You Make Your Next Money Move
The safest way to protect your approval is to ask before you act, not after. A loan officer at Austin Capital Mortgage can review any planned purchase, job change, or deposit against your specific file and tell you whether it is safe to move forward.
For more on the closing process itself, see the CFPB’s guide to the Closing Disclosure.
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