1. Shopping before getting pre-approved
Touring homes before a lender has reviewed your file is how buyers fall for houses they can't finance. It also puts you in a losing position when a competing offer arrives with a pre-approval attached. Fix it by treating pre-approval as step one, not step three.
2. Buying at the top of your approval
Your approval assumes nothing goes wrong. It doesn't account for childcare, a car repair, an escrow increase, or a job change. Buyers who stretch to the ceiling are the ones who discover in year two that they own a house and nothing else. Aim 10% to 20% below the maximum.
3. Forgetting the costs beyond the mortgage
Property taxes, insurance, PMI (private mortgage insurance — an extra monthly fee on conventional loans when you put down less than 20%; it protects the lender, not you, and can usually be removed later), HOA (homeowners association — a neighborhood or condo group that charges a monthly or yearly fee and sets community rules; lenders count that fee in your payment) dues, utilities, and maintenance routinely add 40% to 50% on top of a principal-and-interest quote. Budget from the all-in payment, not the number in the ad.
4. Opening new credit during the process
Financing furniture, a car, or an appliance package before closing changes your DTI (debt-to-income ratio — how a lender measures your monthly bills as a percentage of your monthly income before taxes) and your score. Lenders re-pull credit shortly before funding. This mistake has killed approvals 48 hours before the signing table. Buy nothing on credit until you have keys.
5. Changing jobs mid-process
Even a raise can require re-verification, and a switch to commission or self-employment can restart your qualifying income calculation entirely. If a move is unavoidable, tell your loan officer before you accept, not after.
6. Draining savings to zero at closing
Reserves matter to underwriters, and they matter far more to you. The water heater does not care that you just bought the house. Leave something behind.
7. Skipping or waiving the inspection
In competitive markets buyers waive inspections to win. It is the single most regretted concession in homebuying. If you must be aggressive, shorten the window or agree not to request repairs — but still get the report.
8. Not comparing lenders
Rate, points, lender fees, and mortgage insurance pricing vary meaningfully between lenders on the same borrower profile. Multiple mortgage inquiries within 45 days count as one for scoring purposes, so shopping costs you nothing.
9. Ignoring property taxes and insurance by location
Two identical homes a few miles apart can differ by $300 a month in taxes and insurance. Verify both before you write an offer, especially in flood, wildfire, and hail-exposed markets.
10. Misunderstanding earnest money
Your deposit is protected only by the contingencies in your contract. Waive the financing or appraisal contingency and you've put those funds genuinely at risk. Know which protections you still have before you sign an addendum.
11. Making large undocumented deposits
Cash deposits, transfers from unnamed accounts, and money from an unclosed asset sale all require sourcing. This is the number one cause of last-minute underwriting delays for first-time buyers.
12. Choosing the wrong loan program
FHA (Federal Housing Administration loan — a government-backed loan built for buyers with lower credit scores or smaller down payments) is not automatically the right answer for a first-time buyer, and neither is conventional. The comparison hinges on your credit score, your down payment, and how long you'll hold the loan — because FHA mortgage insurance usually doesn't fall off. Run both.
Frequently asked questions
Which mistake costs the most money?
Buying at the maximum approval. It's not a one-time cost — it compounds monthly for as long as you own the home.
Can I recover if I already opened new credit?
Often yes. Tell your loan officer immediately so the file can be re-run. Hiding it guarantees the problem surfaces at the worst moment.
Is waiving an inspection ever reasonable?
Only with eyes open — on new construction with warranty coverage, or when you've done a pre-offer walkthrough with a contractor. Never on an older home you've seen once.
How do I know if I'm overpaying for the house?
The appraisal is your check. If it comes in below the contract price and you have an appraisal contingency, you have the leverage to renegotiate.
Run your numbers
Take what you just learned and apply it to your file.