Bad Debt Tax Deductions: What Businesses Should Know

Let’s say you invoiced a client company $50,000 for a service you delivered nine months ago. You can’t get in touch with them, so you do a little research, and you find that their business shut down. Even if you could contact them at this point, they probably wouldn’t be able to pay the invoice. While that $50,000 is effectively gone, there is a small silver lining: you can probably get a tax deduction on it.

This is known as “bad debt”. If another business owes your company an amount of money it can’t repay, the IRS often allows a deduction for that total under IRC Section 166. However, whether your particular debt qualifies depends on how it originated, how your business accounts for income, and how thoroughly you’ve documented the life cycle of the invoice.

This guide covers what counts as a business bad debt under federal tax law, the difference between business and nonbusiness debts, the five requirements the IRS looks at before allowing the deduction, and how to document and file it. If you’re looking for an easier way to track active debt, you may want to consider a business banking platform like Slash.¹ Slash not only centralizes all client payments and invoices on one dashboard, but creates an audit trail that can clarify the journey of bad debt from first request to abandonment.

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What Is Bad Debt for a Business?

In accounting terms, bad debt is a receivable that’s become uncollectible. While there are two main ways to account for it, you’re only able to deduct the debt through one of them.

The allowance method, which GAAP (Generally Accepted Accounting Principles) requires, has businesses estimate their uncollectible accounts each period. From there, they record an allowance for doubtful accounts as something called a “contra asset” on the balance sheet, which holds a negative value.

The other way is the direct write-off method, which records the expense only when a specific account is actually deemed uncollectible. Simply put, you record bad debt in the allowance method when you “believe” it’s gone, and you record it in the direct write-off method when you “know” it’s gone.

Naturally, that raises the question: how do you know debt is officially gone? As far as the legal system is concerned, the company that owes you your money must either be bankrupt, insolvent, or completely unreachable. If one of these things is true, and you’ve failed in your attempts to retrieve your bad debt, it’s considered “worthless” and is tax deductible.

However, if you’ve used the allowance method and you haven’t officially confirmed that your client is unable to pay their debt, it’s not tax deductible. The debt must be legally worthless through one of the three factors listed above.

Another thing to note is that cash-basis businesses probably won’t be able to deduct bad debt by the very nature of the way they file income. Because cash-basis taxpayers recognize income when they receive payment rather than when they issue an invoice, they won’t have logged any income or payment in their books. If the income was never technically documented, there's nothing to offset. If you practice accrual basis accounting, though, you should have that expected payment logged and ready to write off.

Business vs. Nonbusiness Bad Debts: Why the Difference Matters

The tax treatment of a bad debt also depends on whether it qualifies as a business bad debt or a nonbusiness bad debt under IRC Section 166.

A business bad debt generates an ordinary loss that’s fully deductible against ordinary income in the year it becomes worthless. A nonbusiness bad debt is treated as a short-term capital loss, which means it can offset capital gains first. However, any excess is limited to a $3,000 annual deduction against ordinary income. That means, if the $50,000 example we gave earlier was nonbusiness bad debt, it could take more than 16 years to fully deduct.

For corporations, all debt is automatically treated as a business bad debt. However, classification for sole proprietors, partnerships, and S corporations depends on whether the debt was acquired as the result of a trade or business. Common business bad debts include credit extended to customers, employee loans, and advances to vendors with a business purpose. An investor making a loan to a startup in which they hold equity, however, would usually be considered a nonbusiness debt.

Some trickier cases involve business owners who personally guarantee a company loan or lend money to their own business. Courts apply a "dominant motivation" test, which determines whether the primary reason for creating the debt was protecting a business interest, such as a salary or business relationship, or protecting an equity investment. If it doesn’t tie closely to your business’s operations, it will likely be considered nonbusiness bad debt.

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When Is Bad Debt Tax Deductible for Businesses? Key IRS Rules

Even if you’ve directly written off the bad debt, it’s connected to your business, and the client is bankrupt or unreachable, it’s still not necessarily tax deductible. IRC Section 166 requires a total of five things before a bad debt deduction is allowed:

An official debtor-creditor relationship: The debt must arise from a legally binding obligation. If the debt comes from an advance with no expectation of repayment or a gift recorded as a loan, it doesn’t qualify. The IRS looks at whether there was a written agreement and whether interest was charged.
An obligation qualifying under IRC Section 166: For individual and pass-through taxpayers, the debt must be tied to a trade or business rather than a personal activity or investment.
An adjusted basis in the debt: In this instance, “adjusted basis” refers to the action you took to account for the payment before it was made. This detail is why finance teams that practice cash-basis accounting probably won’t be able to deduct their debt, as they didn’t make an initial adjustment for it.
Prior income inclusion: The deduction compensates for income that was already taxed. Again, this won’t apply to cash-basis businesses that didn't include the amount in their income.
Worthlessness in the year claimed: Most importantly, the IRS requires evidence that there's no reasonable expectation of repayment. Bankruptcy proceedings, a written legal opinion that the debt is uncollectible, an inability to locate the debtor, and records of collection efforts can all support the claim.

Business bad debt can also be deemed partially worthless, meaning only a portion of the debt has been paid or can ever be paid. Nonbusiness bad debts, on the other hand, must be totally worthless before any deduction applies.

If you miss the year the debt became worthless, you actually have more time than you might think. IRC Section 6511(d) gives taxpayers seven years from the return due date to file a refund claim for a bad debt deduction, which is a lot longer than the standard three-year window for most amended returns. Since companies can spend quite a while waiting and trying to reach out to their debtors, it’s not uncommon for action to take place in the following years. These come through refund claims rather than standard deductions, however.

Strategies to Deduct Business Bad Debt Effectively

As is the case with most situations involving the IRS, documenting everything is step one. It’s wise to start with a written agreement, a signed contract or purchase order, an invoice with payment terms, and a record of delivery or service completion. If your debt comes from a casual agreement, you’re already in a bad spot.

When a receivable begins aging, keep track of the steps you made to try to retrieve it. You might log emails you sent, calls with the debtor or their representatives, written collection notices, referrals to outside counsel, and any response from the debtor. If the debtor files for bankruptcy or you receive a legal opinion that collection isn’t possible, you’ll have a trail that leads from start to finish.

Always remember that you can only deduct a bad debt in the year it becomes worthless, rather than the year the invoice was initially sent. If you’re part of an accrual-basis business, it can be helpful to reach out to your tax advisor to see which accounts should be charged off before year-end and which should be waited on a bit longer.

If you find a missed bad debt deduction from a prior year, check whether you're still within the seven-year window under IRC Section 6511(d). Amending the return to claim the deduction is usually worth doing, especially for large debts.

What Not to Do When Deducting Bad Debt

The IRS requires quite a few factors to be accurate before you’re able to deduct your bad debt. Any mistakes along the way can be costly, whether they’re made in documentation or in filing. Here’s what not to do:

Don't deduct unpaid invoices as a cash-basis business: Cash-basis taxpayers haven't included those amounts in their income, so they won’t have any basis to deduct.
Don't rely on an allowance reserve as your tax deduction: If you accounted for bad debt early as part of the allowance method, it’s documented, but it’s not official. You can only deduct bad debt if it’s been fully written off as a loss.
Don't write off a debt before it's actually worthless: A slow-paying or flakey vendor isn’t the same as a bankrupt vendor. If the debtor is still in business or you haven't documented many collection efforts, the IRS can reject the deduction because there’s still potential for repayment.
Don't misclassify a nonbusiness bad debt as a business one: There’s a big difference between an ordinary loss and a short-term capital loss. If you're an individual or pass-through entity and the debt arose outside your trade or company, you’re subject to the $3,000 annual cap. If you try claiming it as a business debt, the IRS will likely notice, and you’ll be subject to penalties.

Keep Your Documentation In Line With Slash

So your client’s gone bankrupt, the bad debt relates to your business, and you adjusted for the payment as part of accrual accounting. If your working relationship isn’t officially documented, though, the IRS still might not allow you to deduct your debt. Slash can fix this problem before it happens by keeping AR aging reports, payment histories, and vendor transaction data on the same dashboard.

Slash users can export their full transaction history at any time, meaning key points and gaps along their business relationship with a client won’t be lost between disconnected platforms. If you want to find something more specific, you can prompt Slash’s agentic AI assistant to dig through your past data. With simple English prompts, you could ask Twin details about average invoice waiting periods with a client and when repayments first went cold.

As an all-in-one business banking solution, Slash can help users with a lot more than recapturing outstanding debt. We built our platform to bring corporate cards, global payments, stablecoins, working capital, and more onto the same dashboard.⁴,⁵ Some of our features include:

The Slash Visa® Platinum Card: The Slash Card allows you to set customizable spending controls and issue unlimited virtual cards for handling team expenses, vendor payments, subscriptions, and more. Users can also earn up to 2% cash back on business purchases.
High-yield treasury: Earn up to 3.80% annualized yield on idle funds with money market investments from BlackRock and Morgan Stanley, managed directly within your Slash account.⁶
Accounting & ERP integrations: Sync transaction data with QuickBooks Online, Xero, NetSuite, or Sage Intacct to streamline reconciliation, reporting, and month-end close.
Native cryptocurrency support: Send and receive USD-pegged stablecoins USDC and USDT across eight supported blockchains for faster, lower-cost global payments.
Diverse payment methods: Slash supports a wide range of payments, including card spend, global ACH, international wire transfers to over 180 countries via SWIFT, and real-time domestic payments through RTP and FedNow.

If and when your business gets stuck with an unpaid invoice, Slash can help you piece together the financial trail you need to reclaim it.

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This article is educational content, not legal or tax advice. It’s always best to consult a qualified tax professional about your specific situation before filing.

Frequently Asked Questions

Can a cash-basis business ever deduct a bad debt?

If you’re doing cash-basis accounting correctly, the answer should be no. Because cash-basis businesses recognize income only when they receive payment, they have no adjusted basis in accounts receivable and nothing to deduct. The exception is when the business lent actual cash that became uncollectible, such as an employee loan or vendor advance. In those cases, the money left the business, basis exists, and the loss can qualify under Section 166.

How do I prove that a debt is worthless?

You don't need a court judgment, but you will need evidence. Bankruptcy or insolvency proceedings, an inability to locate the debtor, and ignored collection letters are all strong signs that you can’t get the money back.

What happens if a customer pays after I've already deducted the bad debt?

Fortunately, this scenario is pretty simple. Any amount you recover after claiming a bad debt deduction is taxable income in the year you receive it. The same amount recovered is included in income for that later year rather than changing the original deduction, unless another adjustment is required. If you wrote off $50,000 and later get $15,000 in the related settlement, that $15,000 is included in gross income for the settlement year.

Is there a deadline for claiming a bad debt deduction I missed?

Yes, but it’s actually pretty far away. Under IRC Section 6511(d), taxpayers have seven years from the due date of the return for the year the debt became worthless to file a refund claim for a missed bad debt deduction.