Security Lending Write-Off: Turn Capital Losses Into Ordinary Deductions

If you hold a taxable brokerage account with positions sitting on large unrealized losses, you may be stuck behind the $3,000/year capital loss limitation — waiting years to fully deduct what you’ve already lost. The security lending write-off strategy offers a way around that cap by converting those capital losses into ordinary bad debt deductions under IRC §166.

Key Takeaways

• Capital losses are limited to $3,000/year against ordinary income — bad debt deductions are not.
• Lending your securities to short sellers doesn't trigger a taxable sale or reset your holding period.
• If the borrower defaults, your loss qualifies as an ordinary bad debt (IRC §166), fully deductible immediately.
• Lending fee income is ordinary income; dividends on lent shares become substitute payments taxed at ordinary rates.
• Most valuable for large unrealized loss positions where the annual cap creates a long deferral cost.

The $3,000 Problem

When you sell securities at a loss, the IRS limits how much you can deduct against ordinary income: $3,000 per year (or $1,500 if married filing separately). Any excess loss carries forward to the next year, and the year after that. If you have a $30,000 loss, you’re looking at a decade of waiting.

This makes large capital losses worth far less in present value terms than they appear on paper. A $30,000 loss at a 32% marginal rate is theoretically worth $9,600 in tax savings — but spread over 10 years at a 4% discount rate, the real present value is significantly lower.

How Securities Lending Creates an Ordinary Loss

When you lend securities through a broker’s lending program, you’re transferring temporary possession — not ownership — of your shares to a borrower (typically a short seller). The transaction is not a sale. Under Rev. Rul. 78-188, a bona fide securities loan is not a taxable exchange.

If the borrower defaults and cannot return equivalent securities, the IRS treats your claim against the borrower as a bad debt under IRC §166. Ordinary bad debts are fully deductible against ordinary income in the year they become wholly worthless — with no annual cap.

This converts what would have been a capital loss (limited, deferred, slow) into an ordinary loss (unlimited, immediate, fully deductible).

What You Earn While Lending

Beyond the default scenario, lending your securities generates fee income from the borrower, paid through your broker. This is:

• Ordinary income — reported on Form 1099-MISC or as substitute payments on 1099-DIV
• Not tax-free — but it provides cash flow on positions you’d otherwise hold idle

Important tradeoff: While your securities are out on loan, any dividends they pay are received by the borrower. The borrower must compensate you with equivalent “substitute payments in lieu of dividends” — but these are taxed at ordinary income rates, not the lower qualified dividend rate. If you hold high-dividend securities, this cost should be factored into your analysis.

Comparing the Two Scenarios

	Capital Loss (No Lending)	Ordinary Bad Debt (IRC §166)
Annual deduction limit	$3,000/year	Unlimited
Rate	Marginal rate	Marginal rate
When deductible	Spread over years	Year of default
Holding period reset	N/A	No — preserved

For a $30,000 loss position at a 32% marginal rate:

• Capital loss path: $960/year for 10 years, with significant discounting
• Ordinary loss path: $9,600 in the year of default

Implementation Steps

1. Identify large loss positions — Focus on publicly traded securities with significant unrealized losses held more than one year (to preserve LTCG treatment if the loan is repaid and you later sell)
2. Enroll in a lending program — Many major brokers offer fully paid lending or stock yield enhancement programs (Interactive Brokers, Fidelity, Schwab)
3. Review the agreement — Confirm the lending fee rate, term, and borrower obligations
4. Track substitute payments — These are ordinary income, not qualified dividends
5. Document any default — If the borrower defaults, obtain written confirmation and document when the debt became wholly worthless
6. File Form 8949 / Schedule D — Include a bad debt statement claiming the IRC §166 ordinary deduction with your return
7. Consult a tax professional — IRC §166 requires the debt to be a bona fide business debt to qualify for ordinary treatment; proper documentation is essential

Risks and Limitations

• Default risk is low but real — Major broker defaults are rare. This is a hedge on tail risk, not a guaranteed tax benefit.
• Substitute payment cost — Ordinary dividend taxation instead of qualified rates is a real cost on high-yield positions.
• Documentation requirements — The IRS requires a bona fide lending agreement and clear evidence of default for IRC §166 treatment.
• Nonbusiness bad debt risk — If the IRS reclassifies the debt as a “nonbusiness bad debt,” it would be treated as a short-term capital loss — negating the benefit.

How sharper.tax Helps

Identifying which of your positions have large enough unrealized losses to make this strategy worthwhile requires seeing your full tax picture. sharper.tax analyzes your uploaded tax return, detects capital loss carryovers and existing investment income, and models the present value advantage of ordinary loss treatment — giving you the same analysis a high-end CPA would run, for free.

Sources

• IRC §166 — Bad Debt Deduction
• Rev. Rul. 78-188 — Securities Lending Not a Taxable Exchange
• IRS Publication 550 — Investment Income and Expenses
• IRS Topic 409 — Capital Gains and Losses

This article is for educational purposes only and does not constitute tax or legal advice. Consult a qualified tax professional before implementing any tax strategy.