Is Business Loan Interest Tax Deductible?

Is business loan interest tax deductible?

Business loan interest is tax deductible when the borrowed money pays for business expenses. The principal you repay is not deductible, and interest on money spent on personal costs is not business interest.

The business loan interest deduction is a federal tax deduction that lets a business subtract the interest it pays or accrues on business debt from its taxable income. Under 26 U.S.C. §163(a), "There shall be allowed as a deduction all interest paid or accrued within the taxable year on indebtedness."

IRS Publication 334 adds three conditions for interest on a business debt. All of them must hold:

1. You are legally liable for the debt.
2. You and the lender both intend that the debt be repaid.
3. You and the lender have a true debtor-creditor relationship.

A signed business term loan with a repayment schedule is the plain case. An informal loan from family should still be put in writing, with a schedule, so you can show the conditions are met.

Commera is a broker, not a lender. We compare offers from our lender partners. The tax answer comes from the tax rules and your return, not from the lender, so check your own numbers with a tax advisor.

Are business loan payments tax deductible?

Business loan payments are only partly deductible: the interest part is, and the principal part is not. According to 26 U.S.C. §163(a), the deduction covers interest on indebtedness. Repaying principal hands back borrowed money, so it is not an expense.

Principal is not a cost: it is the loan itself going back to the lender.

That does not leave the purchase without a tax benefit. If the loan pays for equipment, you recover the equipment's cost through depreciation, separately from the interest. Our guide to equipment financing explains how those loans are structured.

What part of a loan payment is deductible

Origination and other debt issuance costs follow their own rule. Per 26 CFR §1.446-5, if these costs are otherwise deductible, "they are deductible by the issuer over the term of the debt." The issuer here is you, the borrower.

A forgiven balance runs the other way. Per IRS Publication 4681, you generally must include canceled debt in your income, though exclusions exist.

How the use of the money decides the deduction

The use of the loan money, not the type of loan, decides whether the interest is business interest. IRS Publication 334 puts it plainly: "Interest relates to your business if you use the proceeds of the loan for a business expense."

Collateral does not change that. Per 26 CFR §1.163-8T(c)(1), debt and its interest are allocated "solely by reference to the use of such proceeds." The property that secures the loan does not move the interest from one category to another.

Mixed use splits the interest. Per Publication 334, if a loan is part business and part personal, "you must divide the interest between the personal part and the business part." The personal part brings no deduction for owners who are not corporations. Under 26 U.S.C. §163(h)(1), a taxpayer other than a corporation cannot deduct personal interest.

The same logic applies to a business line of credit. Each draw is traced to what it paid for. A draw that covers payroll is business interest. A draw that covers a family trip is not.

Keep the money traceable. Pay vendors straight from the account that received the loan.

Merchant cash advances, factoring and leases are separate products, and their tax treatment is outside this guide.

Worked example: a business loan with a personal slice

In this Commera illustrative calculation, a sole proprietor deducts $7,479.57 of first-year interest on Schedule C. That is more than a flat split by the use of the money, because the personal part of the loan is repaid first.

Methodology: Commera illustrative calculation with assumed figures, not a loan offer, not tax advice and not a real deal. Both worked examples use one fixed-rate term loan, and its full terms are in the next section. The loan closes on January 1, the tax year is the calendar year, and twelve monthly payments fall in each year. The origination fee is assumed to be withheld from the proceeds.

The calculation covers federal tax only. In this illustrative case, the owner files Schedule C and spends $75,000 of the loan on equipment and inventory and $25,000 on a personal car.

The split changes over time. According to 26 CFR §1.163-8T(d), repayments are treated as paying off the personal part of a debt first. The table follows that rule month by month. The personal part is fully repaid with the payment in month 11, so all the interest in month 12 is business interest.

The business share follows the business money. In this illustrative case, one quarter of the loan went to a personal purchase, but only $1,166.81 of the year 1 interest leaves Schedule C. The personal part shrinks first.

The two rows add up to the total. Consult a tax advisor before you claim the split on your return.

Worked example: what the deduction saves on a term loan

In this Commera illustrative calculation, a C corporation saves $3,393.99 of federal tax over three years on the loan interest and nothing on the principal. The loan below is the one from the Methodology in the previous section.

The rate is not the APR. The estimated APR is an IRR over the 36 payments against the cash actually received. Terms are illustrative and subject to underwriting.

The corporation is taxed at 21% under 26 U.S.C. §11(b). The whole loan funds the business.

What the numbers say:

1. The deduction lowers the cost, not the payment. In illustrative year 1, the tax saved is $1,815.74. The payments in the same row do not get any smaller.
2. The interest costs less after tax. In this illustrative case, the interest net of the federal tax saved is $12,767.85.
3. The saving shrinks each year. Each payment holds less interest and more principal, so the deductible part falls.

The fee is not in the table. According to 26 CFR §1.446-5(b)(1), debt issuance costs are treated as if they adjusted the yield on the debt. The fee is then deducted across the term on that yield basis. Your accountant works out the amount for each year.

Before you borrow, compare business loan offers on their full cost, not on the tax angle. You can also estimate the payment for other amounts and terms.

This calculation is not tax advice. Consult a tax advisor about your own return.

When can the interest deduction be limited?

The interest deduction can be limited when a business is too large to count as a small business taxpayer. According to 26 U.S.C. §163(j)(1), deductible business interest cannot exceed business interest income plus 30% of adjusted taxable income, plus floor plan financing interest.

Most small businesses sit outside that cap. Per the IRS Instructions for Form 8990, "A small business taxpayer is not subject to the section 163(j) limitation and is generally not required to file Form 8990."

A small business taxpayer is one that is not a tax shelter and meets the gross receipts test. The test looks at average annual gross receipts for the three prior tax years. The 2026 figure comes from IRS Revenue Procedure 2025-32, section 4.30.

Above the threshold, two more rules matter. Per IRS Publication 334, for tax years beginning in 2025, adjusted taxable income adds back depreciation, amortization and depletion. A larger adjusted taxable income means a larger cap.

Interest cut by the cap is not lost. According to 26 U.S.C. §163(j)(2), it is treated as paid or accrued in the next tax year.

What records support the deduction?

Records that tie the loan money to business spending support the deduction. Per IRS Publication 334, the debt must be one you are legally liable for, and the link to the business comes from how you use the proceeds. Your records prove both.

Loan interest records checklist

1. Loan agreement and schedule. Keep the signed agreement and the amortization schedule. They show you owe the debt and how each payment splits.
2. Annual interest statement. Ask the lender for a year-end statement of interest paid. Your return starts from that figure.
3. Bank statements. Keep the statements that show where the loan money went. The use of proceeds decides the deduction.
4. A separate business account. Deposit the loan into a business account and pay vendors from it. Mixed accounts make tracing harder.
5. Personal share calculation. If any money went to personal use, write down the amount and how you split the interest. Your tax advisor will ask for it.

State rules can differ from the federal rules. Consult a tax advisor before you file.

Broker disclosure: Commera Finance is a broker, not a direct lender. Financing providers make their own eligibility, underwriting, approval, pricing, and term decisions.