Where to claim mortgage interest on your tax return—and what qualifies

A mortgage's purchase date and interest rate do not establish a deduction. Eligibility also depends on the home, the loan, how the money was used and the applicable limits.

Qualifying home mortgage interest is generally claimed as an itemized deduction on Schedule A, which is filed with Form 1040. A Form 1098 from your lender is a good starting point, but it doesn't make every dollar on it deductible, and it doesn't make itemizing the better choice.

That matters when a refinance offer arrives with tax-savings language. Whether interest is deductible turns on the loan and how its proceeds were used, not on the sales pitch.

Check whether your loan and home qualify

For this deduction, the borrowing must be backed by a qualifying residence: your primary home or an eligible second home. Purchase mortgages and later mortgages can qualify. The signed security document pledges the residence to the lender; applicable state or local law must also recognize that security interest through recording or another legally effective method.

IRS Publication 936 sets out the conditions. In plain terms they ask:

• Does a qualifying primary or second residence back the debt, and do you have an ownership interest in that residence?
• Did you pay the interest, and are you liable for the debt?
• Are you itemizing on Schedule A?
• Did the loan money go toward buying, building or substantially improving the home that secures it?
• Does a debt limit reduce the amount you can count?

Debt limits come next. Under the 2025 instructions, qualifying borrowing dated later than December 15, 2017 generally has a $750,000 limit. The limit for married separate filers is $375,000. Other mortgages and exceptions can affect the calculation; Publication 936 explains those interactions. October 13, 1987 is another important cutoff: borrowing from that date or earlier is grandfathered debt, with special treatment of how its proceeds were used.

What makes interest eligible for the deduction?

Only the interest portion of a payment can count as mortgage interest, so principal and other costs bundled into the payment are separate questions.

Escrow is one example. If your payment includes property tax, the Schedule A instructions say you can include only what the servicer actually paid the taxing authority, and that belongs on a property-tax line. The IRS also says the itemized deduction for mortgage insurance premiums has expired, so a premium on Form 1098 isn't automatically deductible.

Home-equity borrowing needs the same careful review. Interest can qualify only for money spent on the purchase, construction or substantial improvement of the residence backing that debt. The other home, loan and debt-limit requirements still apply.

When a second home can count

A second residence can qualify without any personal stays if it was never offered to others for rental or resale during the year.

A partly rented second residence has a personal-use test. Personal use must exceed both 14 days and 10% of the days rented at a fair price. Falling short makes it rental property rather than a qualifying second home. Generally, only one second residence receives this treatment each year; Publication 936 describes exceptions that allow a switch, including acquiring a new home.

Find the interest amount and supporting records

Several documents each hold a piece of the picture, and each answers a different question. The lender or loan servicer's year-end statement is where most people find the interest figure for taxes, but other records settle whether it qualifies.

• Form 1098: the interest and points your lender reports. It leaves open whether a home mortgage interest limit applies.
• Closing or settlement statement: whether points were charged and how they were labeled, which matters to when they can be deducted.
• Loan and bank records: where each part of the loan money went, which shows whether the uses were buying, building or substantially improving the home.
• Escrow and property tax records: what the servicer actually paid the taxing authority, since only that amount counts toward property taxes.

The IRS says the annual statement should be sent by January 31 of the following year; that is a sending date, not a delivery deadline. If it is missing, contact the lender or servicer. Eligibility does not disappear simply because no form arrived.

What Form 1098 tells you—and what it does not

The IRS describes Form 1098 as a report of mortgage interest a lender received in the course of its business. It is filed for each mortgage separately, and the $600 threshold applies to each one, so a loan with less interest than that may not produce a form. A loan that was sold or replaced can mean statements from more than one company for the same year.

A few boxes are worth knowing. Box 1 shows interest received during the year. Box 2 shows the principal owed at the start of the year, or at origination or acquisition for a loan that began or changed hands that year. Box 4 shows a refund or credit of interest overpaid in an earlier year. Other boxes cover points on a home purchase and notes such as escrowed taxes or insurance.

Notice what the form leaves out. It doesn't say whether your home is a qualified home, how loan proceeds were used or whether a debt limit applies. Those checks are yours. Add up statements if you get several, but test each loan on its own.

Match forms and instructions to the relevant year. For a 2025 return, use that year's Schedule A instructions; separately check the reporting year covered by mortgage-statement instructions.

Enter eligible interest on the right tax forms

Schedule A is where itemized deductions are figured, and its total then feeds Form 1040. If you are asking where to enter mortgage interest on a tax return, the answer is the interest section of Schedule A, on lines 8a and 8b in the 2025 instructions.

The order of work:

1. Gather every Form 1098 for the year, plus closing and loan papers.
2. Confirm each loan is secured by your main or second home and that you own an interest in it.
3. Check how the loan money was used and whether a debt limit applies.
4. Enter the eligible amount on the matching Schedule A line.

Whose statement shows the payment matters. For your own Form 1098, line 8a generally takes the deductible interest and points. When a limit applies, calculate the allowable portion using Publication 936 first. If your deductible payment exceeded the reported figure, the instructions allow the higher amount on that line with an explanation.

Line 8b covers interest reported on another person's Form 1098, such as a co-borrower's. You report your share there.

Line 8 also has a checkbox. For 2025 it applies if you had a mortgage with a balance and put some of the money toward something other than buying, building or substantially improving the home. Interest on proceeds used for those other purposes isn't deductible on lines 8a or 8b, though the IRS says interest tied to business or investment use may be deductible elsewhere on a return.

If your Form 1098 shows a refund of overpaid interest, the instructions say not to subtract it from your deduction, and they point to the Schedule 1 instructions instead.

A filing walkthrough for a home bought in 2023

For a home purchased in 2023, the closing documents establish when the borrowing began. The annual interest statement and records of later borrowing supply the other pieces; the purchase year alone does not establish the deduction.

1. Start with the closing papers. They show the lender, the closing date and whether points were charged and labeled as points.
2. Find the debt-limit group. Compare the borrowing date with the applicable limits. Publication 936 explains how to calculate the allowable amount.
3. Open the year's Form 1098. Read the interest reported and look for any refund of overpaid interest.
4. Follow the money. If the loan bought the home and was never added to or replaced, this goes quickly. If you borrowed more later, trace where each part went.
5. Make the entry. Use line 8a for eligible interest on your own form and line 8b for your share of interest on someone else's.
6. Compare deductions. Add your other itemized deductions and compare the total with your standard deduction.

Decide whether itemizing changes the result

In most cases, the larger allowable deduction produces the lower federal income tax: compare the itemized total with the standard deduction. Special rules can affect the choice.

Two totals get compared. The standard deduction depends on your filing status and the return year, and IRS Publication 501 explains the rules and helps you decide between the two. The other total is everything you could list on Schedule A: mortgage interest, certain state and local taxes with an overall limit, gifts to charity, and medical and dental costs above a set share of income.

If your itemized total comes in below your standard deduction, the interest you paid was still real interest, but it may add nothing to that year's return. Tax software or a licensed preparer can run both versions side by side.

Why interest paid is not the same as tax saved

A deduction lowers the income your tax is figured on. It doesn't cut your tax by the amount you deduct. What it saves depends on your tax rate, your other deductions and whether you itemize at all.

A credit works differently, because it comes off the tax itself. That is why interest paid and tax saved are two separate numbers.

The same logic applies to refinancing. A lower rate alone doesn't establish how much interest you will pay over a particular period, because the loan balance, term and payments matter too. And a bigger deduction is not, by itself, a reason to pay more interest.

Keep refinance and home-equity interest separate

A refinance pays off existing borrowing with a new loan. Refinancing and home-equity borrowing can fall within the mortgage-interest rules, but the loan's label does not establish deductibility. Review what the replacement debt covers and where any additional money went:

• When a new loan only pays off the old mortgage, Publication 936 has its own rules for how that debt is treated.
• When a new loan also puts cash in your hands, interest on money that didn't go toward buying, building or substantially improving the home isn't deductible as home mortgage interest.
• When proceeds served more than one purpose, the instructions say to divide the interest among the uses by following the money.

Keep the closing statement and bank records that show where each part went. They are how that division gets done.

Points require a separate timing check. Refinance points generally must be spread across the mortgage term rather than deducted immediately, even for a primary residence. An exception may allow an immediate deduction for the share attributable to substantial improvements to that residence. That exception requires payment from your own funds and satisfaction of the other IRS tests; the remaining points are spread across the loan term.

If unclaimed points remain when you refinance with the same lender, continue deducting that balance across the replacement loan's term rather than claiming it all immediately.

Questions to ask when a refinance offer mentions tax savings

The Federal Reserve cautions that mortgage ads and mailings are marketing materials. Their tax claims need checking against IRS rules and the loan records, separately from the broader question of whether refinancing is worthwhile.

• Does the offer say how much of the new loan would pay off the old mortgage and how much would come to you as cash?
• If cash is involved, what will it pay for? Use of proceeds is one part of the test; the home, loan qualification and debt limits also matter.
• How would points be treated, and over what period would they be deducted?
• Does the tax claim assume you itemize, and has it been compared with your standard deduction?
• Is the claim in writing, and does it point to an IRS rule instead of a general promise?

Do not confuse a deduction with a mortgage interest credit

A mortgage interest credit has separate eligibility rules. A mortgage credit certificate, or MCC, issued through state or local government may make someone eligible; homeownership and interest payments alone do not.

A deduction reduces taxable income, while a credit reduces tax. Use Form 8396 to calculate this credit, with further guidance in Publication 530. Any credit claimed must also be subtracted from the mortgage-interest deduction.

Check the return before filing—or correct a missed deduction

Before you file, one last pass can catch common slips:

1. Every Form 1098 is accounted for, including any from a lender that held your loan earlier in the year.
2. The home and the secured debt meet the IRS rules, and you've checked who paid and who is liable.
3. You've followed the money for any borrowing beyond the purchase or improvements.
4. A refund of overpaid interest in box 4 is handled the way the instructions describe.
5. Property taxes and escrow payments are kept off the mortgage interest line.
6. You've compared your itemized total with your standard deduction.

A missed deduction may call for Form 1040-X. Amend each tax year separately. The general refund-claim deadline is the later of these periods: 3 years from the original filing, including extensions, or 2 years from tax payment. Early filing generally counts as filing on the due date; extensions and exceptions, including certain disaster relief, can change the deadline.

Not every missed deduction produces a refund. A missed deduction may not change the tax if the corrected itemized total remains below an available standard deduction. Check the applicable rules and the corrected return.

The bottom line

The path from payment records to a claim starts with eligibility, not the size of the lender's reported figure. Keep the security documents, closing papers and records showing where borrowed money went. Review each loan before combining the allowable amounts, especially after refinancing or borrowing additional cash.

Then compare the deductions available for the return year. Usually the larger allowable total lowers federal income tax, but special rules can affect that choice. A certificate-based mortgage interest credit also needs coordination with the deduction.

For a missing statement, shared mortgage, debt limit or earlier return, use the applicable IRS instructions rather than a refinance offer's tax estimate. A licensed tax professional can help apply the rules to an individual return.