You can use your credit card while buying a house, but only for the kind of routine spending you were already doing when you applied. Groceries, gas, a streaming subscription, the utility bill you always put on the card: fine. A new sofa, a laptop, a store financing offer, a cash advance: not fine. Lenders approve your mortgage based on a snapshot of your finances, then pull your credit again right before closing to make sure that snapshot still holds. A single out-of-pattern purchase can raise your debt ratios, drop your score, or trigger an underwriting review that delays or kills the deal.
Why a New Charge Can Push You Over the Line
Your debt-to-income ratio is the number lenders care about most after your credit score. It compares your total monthly debt payments to your gross monthly income, and federal rules require the lender to make a good-faith determination that you can actually repay the loan before approving it.1eCFR. 12 CFR 1026.43 – Minimum Standards for Transactions Secured by a Dwelling That determination leans heavily on DTI.
For conventional loans run through Fannie Mae’s automated system, the back-end DTI generally caps at 45%, with room up to 50% for borrowers with strong compensating factors.2Fannie Mae. Eligibility Matrix FHA loans typically cap at 43%, with similar flexibility for stronger files.
Every dollar you charge raises your minimum monthly payment, and the lender counts that minimum against your DTI. If you’re sitting at 44% and a furniture purchase adds $75 to your minimums, you’ve just crossed 45%. It doesn’t matter that you plan to pay the balance off next month. The underwriter calculates from what the credit report shows today, and that $75 can be the difference between approval and denial.
How Credit Utilization Moves Your Score
Credit utilization is how much of your available revolving credit you’re actually using, and it’s one of the most volatile parts of your score. Credit scoring experts generally recommend staying under 30%; borrowers with the best scores tend to stay under 10%. A single large purchase can blow past those thresholds overnight, especially if you only have one or two cards.
Mortgage pricing works in tiers. A score of 740 or above generally earns the best available rate. Drop into the high 600s and your rate can climb by roughly 0.50 to 0.75 percentage points, which on a $400,000 loan translates to tens of thousands of dollars in extra interest over the life of the mortgage.
These swings can happen even while you’re paying every bill on time. Utilization recalculates every time your card issuer reports a new balance to the bureaus, which usually happens once per billing cycle. A purchase that posts right before the reporting date can hit your score inside a single cycle.
The Pre-Closing Credit Check
Lenders don’t pull your credit once and hope for the best. They run a second check shortly before closing, usually one to three days out, to confirm nothing has changed since approval.3Experian. What Happens if Your Credit Changes Before Closing This refresh is where most credit card mistakes come to light.
The lender is looking for undisclosed debt and new inquiries. If a new inquiry turns up, Fannie Mae guidelines require the lender to investigate whether you took on new debt as a result. If you did, the loan may need to be updated and resubmitted through underwriting.4Fannie Mae. DU Credit Report Analysis That resubmission can push closing by days or weeks, and if the new debt moves your ratios out of bounds, the deal can end there.
A conditional approval is exactly what it sounds like: conditional on nothing changing. The pre-closing pull exists to catch changes, and lenders take it seriously.
What’s Safe to Charge and What Isn’t
Routine spending that was already part of your budget before you applied is generally fine. Groceries, gas, monthly subscriptions, and the utility bills you’ve always paid with a card won’t raise flags, because they don’t change your profile. The underwriter expects you to keep living your life.
Problems start with purchases outside your normal pattern:
- Furniture and appliances for the new home. This is the most common mistake. The pull to furnish the place before you move in is strong, but a $3,000 couch on a credit card can derail the whole transaction. Wait until after closing.
- Electronics and other big-ticket items. A new laptop or TV that spikes your balance above 30% utilization hits your score fast.
- Store financing offers. “No interest for 12 months” still opens a new line of credit, which triggers a hard inquiry and adds a new account to your report. Even with a zero balance, the inquiry alone can shave points off your score.
- Cash advances. These carry high fees and interest, raise your balance immediately, and read as financial stress to anyone reviewing your credit.
The safest approach is boring. Spend the way you were spending when the lender first approved you. No new accounts, no large purchases, no balance transfers. If it would change any number on your credit report, postpone it.
Don’t Pay Off a Big Balance Without Calling Your Lender First
If running up a card is bad, paying it off must be good, right? Not always. A large lump-sum payment on a credit card right before closing can cause two separate problems.
First, it drains your reserves. Lenders verify that you have enough liquid funds for the down payment, closing costs, and a cushion. Wipe out $5,000 in savings to clear a card and you might fall below the reserve requirements for your loan program. Second, large unexplained transfers trigger sourcing questions. The lender will want to document where the money came from and may ask for bank statements, gift letters, or other paperwork, all of which cost time your closing timeline doesn’t have.
If you want to pay down a balance before closing, coordinate with your loan officer first. They can tell you how much you can afford to pay without jeopardizing your reserves and can time the payment so the lower balance shows up on your credit report before the pre-closing check.
Fixing a Mistake You’ve Already Made
If you’ve already charged something you shouldn’t have, there are tools, though none of them are instant.
The fastest option is rapid rescoring. Your lender initiates it (you can’t do it yourself) and asks the credit bureaus to update your report with new information, like a paid-down balance. Rapid rescores typically take three to five business days, much faster than waiting for the next regular reporting cycle.5Equifax. What Is a Rapid Rescore? The lender then re-evaluates your file on the updated data. If paying the balance down restores your score and DTI to qualifying levels, the loan can proceed.
Your lender may also ask for a letter of explanation: a short, factual statement describing what happened and why. If you opened a new line or made an unusual purchase, the letter gives the underwriter context. It won’t erase the debt or the inquiry, but it shows you understand the issue and that it isn’t part of a broader pattern. Attach any supporting documents, like a receipt showing you’ve already paid the balance, and have any co-borrower sign it too.
Neither fix is guaranteed, and both eat into your timeline. Prevention is still the better plan.
A Note on Authorized User Cards
If you’re an authorized user on someone else’s credit card, that account can complicate your mortgage in ways you might not expect. For loans processed through Fannie Mae’s Desktop Underwriter, authorized user tradelines are generally included in the automated analysis like any other account. For manually underwritten loans, those accounts are excluded from the decision unless the primary cardholder is also a borrower on the mortgage or you can prove you’ve been making the payments yourself for at least 12 months.6Fannie Mae. Authorized Users of Credit
There’s an important exception. If the primary cardholder is your spouse and your spouse isn’t on the mortgage application, the authorized user account must be considered no matter how the loan is underwritten.6Fannie Mae. Authorized Users of Credit If your spouse runs up a balance on a card where you’re an authorized user, that minimum payment lands in your DTI even though you didn’t make the purchase. If this describes you, ask your loan officer whether removing yourself as an authorized user before closing would help or hurt.
When You Can Actually Start Spending Again
Signing the closing documents doesn’t lift the restriction. A mortgage isn’t complete until the lender funds the loan and the deed is recorded with your local government office. In many areas, recording happens the same day as signing, but it can take several hours or occasionally a full business day. During that gap, the lender can still technically pull funding if they discover new debt.
Wait for explicit confirmation from your escrow officer, title company, or real estate agent that the deed has been recorded and the loan has funded. Once the public record reflects your ownership and the money has been disbursed, you’re free to open new accounts, finance furniture, or make whatever purchases you’ve been holding off on. That confirmation usually comes as a call, email, or text on closing day. Until you have it, keep the card in your wallet for anything beyond your normal routine.