Mistake 1 — Treating your score as pass/fail
Mortgage pricing moves in tiers, usually every twenty points. A 679 and a 680 can be a materially different rate and a different 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) factor on the same loan. Before you accept your quote, ask your loan officer what the next tier up would save — sometimes twelve points of score is worth thousands of dollars.
Mistake 2 — Carrying high utilization
Utilization is the fastest-moving factor in your score. Getting each card under 30% of its limit helps; getting under 10% helps more. Because balances report on statement dates, paying before the statement closes — not before the due date — is what actually changes the reported number.
Mistake 3 — Closing old credit cards
An old card with no balance is helping you in two ways: it lengthens your credit history and adds available limit that lowers utilization. Closing it does the opposite of both. Leave it open, put a small recurring charge on it, and autopay it.
Mistake 4 — Paying collections at the wrong moment
Paying an old collection can restart recency on some scoring models and briefly lower your score. Some programs require it paid, some don't. Ask your loan officer for the program's actual requirement before you pay anything — the right move is sometimes to pay it through closing instead.
Mistake 5 — Believing rate shopping hurts your credit
Multiple mortgage inquiries inside a 45-day window count as a single inquiry for scoring purposes. Getting three quotes is free and routinely saves more than any other hour you'll spend in this process.
Mistake 6 — Not checking your reports for errors
A meaningful share of credit reports contain an error — a paid account showing as open, a duplicate collection, an account that isn't yours. Disputes take 30 to 45 days, which is why this belongs at the beginning of your timeline, not after you're under contract.
Frequently asked questions
How fast can I raise my score?
Utilization changes can show up in 30 to 60 days. Derogatory items take much longer, and time is the only reliable cure for a recent late payment.
Which score do mortgage lenders use?
Typically older FICO models pulled from all three bureaus, with the middle score used for qualifying. That number is often lower than the score shown in a consumer app.
Will being added as an authorized user help?
It can, when the primary account is old, low-utilization, and never late. It's most effective for thin credit files.
Is 580 enough to buy a home?
FHA allows 3.5% down at 580, but pricing at that tier is meaningfully worse. If you can get to 620 or 680 first, the savings usually justify the wait.
Run your numbers
Take what you just learned and apply it to your file.