How to Claim a Partially Worthless Bad Debt Deduction

To claim a partially worthless bad debt deduction, an accrual-method business formally charges off the uncollectible portion of a bona fide business debt on its books during the tax year and deducts that same amount on its return. The deduction is capped at what you actually charge off, and it’s available under Section 166 of the Internal Revenue Code only for debts tied to your trade or business.¹

Confirm the Debt Qualifies

Three gates decide whether a partial write-off is even on the table.

First, the debt has to be a business debt. Partial deductions are available only for debts created or acquired in connection with your trade or business. Nonbusiness debts — a personal loan to a friend or relative, for instance — cannot be partially written off. They must be totally worthless before anything is deductible, and the loss is then treated as a short-term capital loss rather than an ordinary deduction.¹

Second, the obligation must be a bona fide debt. Treasury Regulation 1.166-1(c) defines that as a debt arising from a debtor-creditor relationship based on a valid and enforceable obligation to pay a fixed or determinable sum of money. A gift or capital contribution doesn’t qualify no matter what the paperwork says.² A written promissory note, a stated interest rate, a repayment schedule, and a history of actual payments all help show the arrangement was a real loan.³

Third, you need tax basis in the debt. You either loaned actual cash or previously reported the amount as income. This is where most cash-method businesses lose out. A consultant on the cash method who bills $15,000 and never gets paid never reported the $15,000 as income in the first place, so there is nothing to deduct.³ Accrual-method businesses report income when earned, so a receivable already included in taxable income has basis and can support a partial deduction.

Pin Down the Uncollectible Amount

You don’t have to prove the debtor will never pay another dollar. You do have to identify a specific amount that is realistically gone. If a customer owes $100,000 and has $40,000 in reachable assets, the $60,000 gap is what the deduction targets.

The IRS has said there’s no single test. In Revenue Ruling 2001-59, it identified events that, taken together, support a finding of worthlessness:⁴

Bankruptcy filing, which limits recovery for unsecured creditors.
Insolvency — the debtor’s liabilities exceed assets even without a formal filing.
A serious financial reversal that has destroyed the debtor’s ability to pay.
Disappearance or death, where the debtor can’t be located or the estate is insufficient.
Repeated refusal to pay after demand letters and collection attempts.
Expiration of the statute of limitations, so the debt is no longer legally enforceable.

Facts on the other side weaken the claim. If the debtor is still making interest payments, has significant earning capacity, or the debt is secured by valuable collateral, the IRS will push back. So will a record showing you never really pressed for collection, or that you kept advancing new money after the trouble started.⁴

You must show reasonable collection efforts. A lawsuit isn’t required if you can demonstrate a judgment would be uncollectible anyway, but you need evidence you tried.³ Keep demand letters, phone logs, correspondence with the debtor’s bankruptcy counsel, and any collection agency reports organized by date. An auditor will ask for them first.

Charge It Off on Your Books

This is the step that separates a partial deduction from a total one, and skipping it kills the deduction. Treasury Regulation 1.166-3 requires the uncollectible portion to be formally charged off on your books during the same tax year you claim the deduction, and the deduction cannot exceed the amount actually charged off.⁵

A charge-off is a general ledger entry that reduces the receivable. If a $10,000 debt is 50% uncollectible, you reduce the receivable by $5,000 on your books and deduct $5,000 on the return. Leave the full $10,000 on the balance sheet and the deduction will be denied on audit. The IRS treats the charge-off as proof you’ve genuinely written off that portion rather than keeping options open.

One useful protection: if the IRS disallows a partial charge-off for a given year and the debt later becomes further worthless, you can claim a deduction in that later year for the earlier charged-off amount plus any additional charge-off, provided you consistently maintained the original entry on your books.⁵

Report It on the Right Return

Where the deduction goes depends on your entity type. Corporations report bad debts on Form 1120, Line 15.⁶ Sole proprietors use Schedule C (Form 1040), Part V (Other Expenses), Line 48.⁷ Partnerships and S corporations report on their own returns, with the deduction flowing through to partners or shareholders.

Attach a statement identifying the debtor, when the debt arose, what collection efforts you made, why you determined the specific amount is uncollectible, and the date and amount of the charge-off. Have the general ledger entries — date, original balance, charged-off amount — ready to produce if the IRS asks.

You Have Seven Years to Claim a Refund

Bad debts come with a longer refund window than ordinary items. Under Section 6511(d)(1), a refund claim tied to a bad debt deduction can be filed within seven years from the original return due date, rather than the usual three.⁸ The longer period reflects how hard it is to pin worthlessness to a specific year. It also covers situations where the deduction created or increased a net operating loss that carried into other years.

If the Debtor Later Pays

If money comes in on a debt you already deducted, the tax benefit rule in Section 111 applies. You include the recovered amount in gross income, but only to the extent the original deduction actually reduced your tax.⁹ If the deduction produced no tax savings — for example, it landed in a loss year and the carryover expired unused — you don’t report the recovery as income.

Recovered amounts go on your business return as “Other income” in the year you receive payment.⁷ If the original deduction fed an NOL carryover that hasn’t yet expired, the IRS treats the deduction as having reduced tax, and the recovery is taxable. Keep records of what you deducted and when so you can calculate how much of any later payment counts as income.

1
Office of the Law Revision Counsel. 26 USC 166 – Bad Debts
2
eCFR. 26 CFR 1.166-1 – Bad Debts
3
Internal Revenue Service. Topic No. 453, Bad Debt Deduction
4
Internal Revenue Service. Revenue Ruling 2001-59
5
eCFR. 26 CFR 1.166-3 – Partial or Total Worthlessness
6
Internal Revenue Service. 2025 Instructions for Form 1120
7
Internal Revenue Service. Instructions for Schedule C, Form 1040
8
Office of the Law Revision Counsel. 26 USC 6511 – Limitations on Credit or Refund
9
Office of the Law Revision Counsel. 26 USC 111 – Recovery of Tax Benefit Items