Shareholder Loan vs. Capital Contribution Tax Treatment

When you put your own money into a closely held corporation, structuring it as a shareholder loan gives the corporation an interest deduction and gives you a contractual right to repayment with interest, while structuring it as a capital contribution increases your stock basis but locks the money into the corporation’s equity with no repayment obligation. The tax treatment of a shareholder loan versus a capital contribution differs at every stage: going in, while the money sits there, coming back out, and if the business fails. Most experienced advisors put in a mix of both, and the reasoning below explains why.

How the Two Are Taxed Side by Side

A shareholder loan is a debtor-creditor arrangement. You lend, the corporation owes, and the note sets a rate and a schedule. The corporation deducts the interest it pays you as a business expense.¹ You report that interest as ordinary income. Principal repayments are just your own money coming back, so they are not taxable.

A capital contribution is an equity investment. It is not taxable income to the corporation, and the corporation gets no deduction for receiving it.² Your stock basis increases by what you contributed. There is no interest, no maturity date, and no repayment obligation. The tax event is deferred until money comes back to you through a distribution, a dividend, or a stock sale.

A few limits sit on top of the interest deduction. A corporation generally cannot deduct business interest exceeding the sum of its business interest income plus 30 percent of its adjusted taxable income, with disallowed interest carrying forward.¹ A small business exception applies where three-year average gross receipts stay under the inflation-adjusted threshold, which is $31 million for 2025.³ Most closely held corporations sit well under that ceiling.

Two smaller traps go with the loan side. If you own more than 50 percent of the stock and the corporation is on the accrual method while you file on the cash method, the corporation cannot deduct accrued interest until you actually receive it and report it.⁴ The deduction is deferred, not lost, but a corporation that has been booking deductions for unpaid interest can face a large adjustment on audit. And the interest you receive can be hit by the 3.8 percent Net Investment Income Tax if your modified adjusted gross income exceeds $250,000 for a joint return or $200,000 single.⁵

You Have to Charge at Least the AFR

A zero-interest or below-market loan from a shareholder to a corporation does not simplify anything. Under the imputed interest rules, the IRS treats the shortfall between what you charged and the Applicable Federal Rate as if the corporation distributed that amount to you and you paid it back as interest.⁶ Both sides pick up income on money that never moved.

The rate you need to charge tracks the loan’s term. The short-term AFR applies to demand loans and to term loans of three years or less. The mid-term rate covers loans between three and nine years. The long-term rate covers anything over nine years. For a term loan, the applicable rate is locked in on the day the loan is made.⁶ The IRS publishes updated AFRs monthly.

One narrow exception: if all outstanding loans between you and the corporation stay at $10,000 or less in aggregate, the imputed interest rules don’t apply, unless a principal purpose of the arrangement is tax avoidance.⁶ Above that, charging at least the AFR is non-negotiable.

Why S Corporation Owners Care Extra

If your business is an S corporation, the loan-versus-contribution choice picks up an extra dimension. S corporation losses flow through to your personal return, but you can only deduct them up to the sum of your stock basis and your debt basis from loans you personally made to the corporation.⁷ Debt basis only exists if you loaned money. A capital contribution builds stock basis alone.

Say you have contributed $50,000 in equity and loaned $50,000. Your stock basis is $50,000 and your debt basis is $50,000, giving you $100,000 to absorb pass-through losses. Put the entire $100,000 in as equity and you still have $100,000 of total basis, but ordering rules mean losses cut stock basis first; once stock basis hits zero, excess losses reduce debt basis.⁸

There is a twist to know about. If your debt basis has been reduced by losses and the corporation later repays part of the loan, the repayment is taxable to you to the extent it exceeds the reduced debt basis.⁸ Debt basis restores as future income flows through, but the timing rarely matches your repayment schedule.

The Real Risk: The IRS Calling Your Loan Equity

The biggest hazard on the loan side is recharacterization. If the IRS reclassifies your loan as a capital contribution, the corporation loses every interest deduction it ever claimed, and the principal repayments you already received can be treated as taxable dividends. Add penalties and interest, and the bill compounds.

Congress authorized regulations distinguishing debt from equity and listed factors including whether a written unconditional promise to pay exists, whether the debt is subordinated to other creditors, the corporation’s debt-to-equity ratio, whether the instrument is convertible into stock, and whether loan holdings are proportional to stock ownership.⁹ No final regulations have been issued, so courts weigh these and other factors case by case. No single factor decides the question.

The patterns that most often sink a shareholder loan:

No promissory note with a fixed maturity date and stated interest rate.
Interest and principal that fall due on paper but never actually get paid, with no one demanding payment.
Thin capitalization. A debt-to-equity ratio above 3:1 draws heightened scrutiny, though there is no bright-line safe harbor in the code.
Loans made in exact proportion to stock ownership, which look like everyone increased their equity and called it debt.
Subordination behind every outside creditor, so your position in a liquidation is functionally equity.
Terms no unrelated bank would have offered the corporation.

The burden sits on you. The IRS does not have to prove your loan is equity; you have to prove it is real debt.

Documentation That Holds Up

A shareholder loan needs the paperwork an outside lender would have kept. At minimum, a written promissory note signed by both parties setting out the principal, an interest rate at or above the AFR, a fixed maturity date, and a repayment schedule. The rate should look like what an unrelated lender would have charged for similar financing.

The board of directors has to formally authorize the loan in a resolution recorded in the corporate minutes, identifying the borrower, amount, interest rate, timeline, and confirming the corporation can service the debt. If the loan is secured, perfect the security interest properly, which for most personal property collateral means filing a UCC-1 with the appropriate state office.¹⁰ The corporation must also issue Form 1099-INT reporting interest of $10 or more paid to you.¹¹ Skipping the 1099 signals to an auditor that neither party is treating this as real debt.

Then actually make the payments. Keep an amortization schedule. Record every payment. If a payment has to be missed or deferred, document the reason and formally amend the note. Quietly letting a missed payment slide is exactly the behavior that produces a recharacterization argument.

Capital contributions need less paperwork but should still be formal. The board should pass a resolution accepting the contribution, and the corporate records should reflect the updated equity accounts and the increased stock basis. Accurate basis tracking drives the tax result for every future distribution and, in an S corporation, controls whether you can deduct pass-through losses.⁸

Getting the Money Back

Loan repayments follow the note. The corporation pays on schedule without needing new board approvals. Principal is not taxable to you. Interest is deductible to the corporation and ordinary income to you. This clean path is a big part of why shareholders use loans in the first place. If the corporation cannot make a scheduled payment, amend the note in writing; unenforced defaults are prime evidence for the IRS.

Pulling capital contributions back out is harder and usually taxed worse. There is no repayment obligation, so the money comes out as a distribution, a dividend, or a stock redemption, each requiring board approval. In a C corporation, distributions are dividends to the extent of accumulated or current earnings and profits, taxed at qualified dividend rates.¹² Only after earnings and profits are exhausted do you get a tax-free return of capital that reduces your basis. Anything past your remaining basis is a capital gain.

A stock redemption can qualify for capital gain treatment if it meaningfully reduces your ownership percentage. If it does not meet the redemption tests, the payment is treated as a dividend.¹³ For a sole shareholder of a closely held corporation, meeting those tests is difficult without bringing in outside buyers. State law adds another layer: before any distribution, the board generally has to confirm the corporation can still pay its debts as they come due and that assets exceed liabilities after the distribution. Directors who authorize distributions violating solvency requirements can face personal liability.

For S corporations, distributions generally come out tax-free up to the Accumulated Adjustments Account balance and your stock basis, which softens this side of the comparison considerably.

If the Business Fails

Structure also drives what a loss looks like on your return.

If the corporation cannot repay your loan and the debt becomes worthless, treatment depends on whether the loan is a business or nonbusiness bad debt. A business bad debt is one created in connection with your trade or business, with a business-related primary motive; it can be deducted in full as an ordinary loss.¹⁴ Most shareholder loans to closely held corporations end up classified as nonbusiness bad debts, because the primary motive is protecting the investment. A nonbusiness bad debt has to be totally worthless before you can deduct it, and it is treated as a short-term capital loss regardless of how long you held the note.¹⁵ Only $3,000 of net capital loss offsets ordinary income each year, with the rest carrying forward.

If your stock becomes worthless, you claim it under the worthless securities rules, treated as though you sold the stock for zero on the last day of the tax year. That produces a long-term capital loss if you held the stock more than a year. The same $3,000 annual cap against ordinary income applies. An ordinary loss exception exists for shareholders of affiliated corporations meeting specific ownership and gross receipts tests, but it primarily benefits corporate shareholders rather than individual owners of closely held businesses.¹⁶

So a loan that qualifies as a business bad debt gives you the fastest write-off. A capital contribution locks you into the capital loss track.

Picking a Mix

Going all-in on either structure is rarely the right call. A blend gives you current interest deductions and a clear repayment mechanism on the loan side, and enough equity to keep the debt-to-equity ratio defensible against recharacterization. The equity portion also builds stock basis for absorbing S corporation losses and future distributions.

The right ratio depends on how the corporation is already capitalized, its cash flow for servicing debt, and whether it is a C or S corporation. In an S corporation, the debt basis advantage makes loans particularly valuable through loss years. In a C corporation, the interest deduction only helps if the corporation is profitable enough to use it and if Section 163(j) does not limit it. Whatever split you choose, the paperwork has to be in place from day one. Cleaning up sloppy documentation after an IRS notice arrives is far harder than doing it right at the start.

1
Office of the Law Revision Counsel. 26 USC 163 – Interest
2
Office of the Law Revision Counsel. 26 USC 118 – Contributions to the Capital of a Corporation
3
Internal Revenue Service. Questions and Answers About the Limitation on the Deduction for Business Interest Expense
4
Office of the Law Revision Counsel. 26 U.S. Code 267 – Losses, Expenses, and Interest With Respect to Transactions Between Related Taxpayers
5
Office of the Law Revision Counsel. 26 U.S. Code 1411 – Imposition of Tax
6
Office of the Law Revision Counsel. 26 U.S. Code 7872 – Treatment of Loans With Below-Market Interest Rates
7
Office of the Law Revision Counsel. 26 U.S. Code 1366 – Pass-Thru of Items to Shareholders
8
Internal Revenue Service. S Corporation Stock and Debt Basis
9
Internal Revenue Service. Internal Revenue Bulletin 2016-17
10
Cornell Law Institute. Uniform Commercial Code 9-311 – Perfection of Security Interests in Property Subject to Certain Statutes, Regulations, and Treaties
11
Internal Revenue Service. Instructions for Forms 1099-INT and 1099-OID
12
Internal Revenue Service. Topic No. 404, Dividends and Other Corporate Distributions
13
Office of the Law Revision Counsel. 26 USC 302 – Distributions in Redemption of Stock
14
Internal Revenue Service. Topic No. 453, Bad Debt Deduction
15
Office of the Law Revision Counsel. 26 U.S. Code 166 – Bad Debts
16
eCFR. 26 CFR 1.165-5 – Worthless Securities