Imputed Interest

Imputed interest is the interest income, and the matching deemed payment, that the Internal Revenue Code assigns to a transaction whose stated interest falls short of the applicable federal rate. The Code does not use the phrase; it is the working label for three related regimes. Section 7872, headed "Treatment of loans with below-market interest rates," covers loans and speaks of "forgone interest," the excess of what the loan would have carried at the AFR over what it carries. Section 483, "Interest on certain deferred payments," covers payments on the sale of property and speaks of "total unstated interest." Section 1274 covers debt instruments given for property and rebuilds their issue price around an "imputed principal amount." In each case the effect is the same: the lender or seller is taxed on interest at the market rate whether or not anyone paid it, and the transaction is recharacterized to match.

The loan rules come first because they reach ordinary households. Section 7872 applies to a "below-market loan," which for a demand loan means one where "interest is payable on the loan at a rate less than the applicable Federal rate," and for a term loan means one where "the amount loaned exceeds the present value of all payments due under the loan." The section then lists the loans it reaches: gift loans, compensation-related loans between an employer and employee or a contractor and client, corporation-shareholder loans, loans with tax avoidance as a principal purpose, other loans the regulations pick up, and loans to qualified continuing care facilities, which subsection (h) then largely exempts. The category decides the character of what is deemed to move. On a gift loan the deemed transfer from lender to borrower is a gift; on a compensation-related loan it is compensation; on a corporation-shareholder loan it is a dividend. What comes back the other way is always the same thing: interest, taxable to the lender.

Two mechanics apply depending on the loan's shape. For a gift loan or a demand loan, section 7872(a)(1) provides that "the forgone interest shall be treated as (A) transferred from the lender to the borrower, and (B) retransferred by the borrower to the lender as interest," and (a)(2) times the pretend transfers "on the last day of such calendar year." Forgone interest is defined in (e)(2) as the excess of the interest that "would have been payable on the loan for the period if interest accrued on the loan at the applicable Federal rate" over "any interest payable on the loan properly allocable to such period," with the rate compounded semiannually. The statute spells it "forgone"; "foregone" is a common variant of the same word. For a term loan that is not a gift loan, subsection (b) uses a different device: the lender is treated as having transferred to the borrower, on the day the loan was made, cash equal to the excess of the amount loaned over the present value of the payments due, and the loan is treated as carrying original issue discount in that amount, so the interest is taken into account over the loan's life rather than year by year at the AFR.

The dollar rules are statutory and have not moved since enactment. Section 7872(c)(2) provides that "In the case of any gift loan directly between individuals, this section shall not apply to any day on which the aggregate outstanding amount of loans between such individuals does not exceed $10,000," but (c)(2)(B) withdraws the exception from "any gift loan directly attributable to the purchase or carrying of income-producing assets." A parallel $10,000 exception in (c)(3) covers compensation-related and corporation-shareholder loans, and its kill switch is different: it fails where tax avoidance is a principal purpose of the interest arrangement. Then (d)(1)(A) limits the income-tax side of gift loans above the $10,000 line: "For purposes of subtitle A, in the case of a gift loan directly between individuals, the amount treated as retransferred by the borrower to the lender as of the close of any year shall not exceed the borrower's net investment income for such year," a limitation that stops applying on any day the loans between the two people exceed $100,000, is switched off for tax-avoidance arrangements, and treats a borrower's net investment income of $1,000 or less as zero. Note what the cap does not do: it limits the interest income imputed to the lender, not the gift that the forgone interest represents for gift-tax purposes.

The sale rules divide the remaining ground between two sections by the size and kind of the transaction. Section 1274 applies to a debt instrument "given in consideration for the sale or exchange of property" where some payments fall due more than six months out and the instrument lacks "adequate stated interest," meaning its stated principal exceeds the present value of its payments at the AFR; the issue price becomes the imputed principal amount and the difference is original issue discount. Section 1274(c)(3) then carves out a list that sends smaller and more personal transactions to section 483 instead: sales of farms for $1,000,000 or less by individuals and small businesses, sales of principal residences, sales where total payments do not exceed $250,000, publicly traded debt, certain patent sales, and the related-party land transfers governed by 483(e). Section 483 reaches payments due more than six months after a sale under a contract with some payments due more than a year out, treats part of each payment as "total unstated interest," and does not apply at all where the sales price cannot exceed $3,000. The practical consequence for a seller who finances a buyer at a token rate is that a slice of each installment that was expected to be capital gain, or a return of basis, is ordinary interest income instead.

1. Find the benchmark. Look up the applicable federal rate for the month the loan is made and for its term. A demand loan is tested against the federal short-term rate for each period it is outstanding; a term loan is tested once, at the rate in effect when it was made.

2. Compare the stated interest with the benchmark. If the loan carries at least the AFR, the rules do not apply. If it carries less, the shortfall is the forgone interest for a gift or demand loan, or the excess of the amount loaned over present value for a term loan.

3. Check the two dollar rules. A gift loan between individuals of $10,000 or less is outside section 7872 entirely unless the money bought income-producing assets. A gift loan of $100,000 or less caps the interest imputed to the lender at the borrower's net investment income, treated as zero if it is $1,000 or less.

4. Report the deemed payments. The lender reports the forgone interest as interest income. On a gift loan the same amount is a gift from lender to borrower, tested against the annual gift tax exclusion; on a compensation-related loan it is wages or contractor pay; on a corporation-shareholder loan it is a dividend.

Suppose a parent lends a daughter $200,000 interest-free, repayable on demand, to buy a first home, and the applicable rate for the year is 4 percent. That rate is illustrative only; the real AFR changes monthly and the statute compounds it semiannually, which this example ignores for clarity. The forgone interest for a full year is 4 percent of $200,000, or $8,000. Because the loan exceeds $100,000, the net-investment-income cap is unavailable, so the parent reports $8,000 of interest income she never received and is treated as having made an $8,000 gift to her daughter. Now shrink the loan to $60,000 for a daughter whose net investment income is $1,500. The forgone interest is $2,400, but the loan is under $100,000, so the amount imputed to the parent as income is capped at $1,500. If the daughter's net investment income had been $900 instead, it would be treated as zero and no interest income would be imputed at all, though the $2,400 would still count as a gift.

Pros

• The rules are mechanical and public: the benchmark is a published rate, and a loan that meets it is taken at face value with no imputation.
• The $10,000 exception keeps ordinary family lending, a car repair or a security deposit, out of the statute altogether.
• The $100,000 cap can reduce the imputed income on a family loan to a modest figure, or to zero, where the borrower has little investment income.
• Charging the AFR is usually far cheaper for the borrower than a commercial loan, so compliance costs the family little.

Cons

• A lender is taxed on interest never received, and cannot avoid it by calling the loan interest-free.
• The $100,000 cap limits the lender's income-tax exposure but not the gift: the full forgone interest is still a transfer for gift-tax purposes.
• The two $10,000 exceptions have different kill switches, and using gift loan proceeds to buy income-producing assets defeats the one families rely on.
• A seller who finances a sale at a token rate finds part of each payment recharacterized as ordinary interest income rather than capital gain.