What Is an Incurred Expense? Rules, Timing, and Tax Deductions

An incurred expense is a cost you owe the moment you receive a good or service, even if the invoice hasn’t arrived and no money has left your account yet. So the question “what is an incurred expense” comes down to timing: the obligation exists when the economic event happens, not when you write the check. That distinction shapes how the cost appears on your books and, depending on your accounting method, when you can deduct it on your tax return.

What “Incurred” Actually Means

You incur an expense when you receive something of value and owe for it. A restaurant that takes delivery of produce on credit has incurred the cost the moment the truck pulls away, regardless of the payment terms on the supplier’s invoice. The debt is real; only the payment is deferred.

On financial statements, incurred-but-unpaid costs fall into two buckets. Accounts payable covers amounts already invoiced with a specific figure — the supplier billed you $3,000, and you owe $3,000. Accrued liabilities cover costs that have built up but haven’t been billed yet, like employee wages earned through the end of the month before payroll runs. Accrued amounts are often estimates from contracts or time logs, trued up when the final bill arrives. Either way, both represent money you owe now.

Incurred vs. Paid

The gap between incurring and paying is where confusion lives. You incur the cost when you consume the resource. You pay it when money leaves your account. A business that hires a consultant in June has incurred the expense in June. If the consultant’s invoice isn’t due until August, the payment happens in August, but the obligation existed for two months before any cash moved.

Looking only at what you’ve paid gives you a distorted picture. Tracking what you’ve incurred forces an honest view of what’s actually committed, which matters whether you’re a freelancer projecting quarterly taxes or a company reporting results.

Does the Timing Affect Your Taxes?

Your accounting method decides that. Under the cash method, you deduct expenses in the year you pay them. Under the accrual method, you deduct them in the year you incur them, which is often earlier.

Most individuals and small businesses use the cash method because it’s simpler: money in, money out. The IRS requires certain businesses to use accrual, though. For tax years beginning in 2026, a business with average annual gross receipts above $32 million over the prior three tax years must use the accrual method if inventory is necessary to account for income.¹ Businesses below that threshold generally qualify as small business taxpayers and can stay on cash.²

If you’re on the cash method, the incurred-vs-paid distinction still matters for your books, but your tax deductions follow payment dates. If you’re on the accrual method, the rules below control exactly when a cost counts as incurred for tax purposes.

The All Events Test

For accrual-method taxpayers, federal regulations spell out when a liability is treated as incurred. Under 26 C.F.R. § 1.461-1, three conditions must all be met in the same tax year:

Fact of liability: All events establishing the obligation have occurred, with no remaining contingency that could wipe out the debt.
Determinable amount: The dollar figure can be calculated with reasonable accuracy, even if it isn’t nailed down to the penny.
Economic performance: The service was actually provided, the property was delivered, or the relevant activity took place.

All three matter. A contractor who has agreed to paint your office but hasn’t started yet gets you nowhere: the signed contract may establish the fact of liability, but economic performance hasn’t occurred.³

When Economic Performance Happens

The regulations set different triggers depending on the type of cost:

Services or property provided to you: Economic performance occurs as the services are performed or the property is delivered. Legal work performed in November is incurred in November, even if the bill arrives in January.
Your use of someone else’s property: Economic performance occurs ratably over the period of use. A 12-month office lease means one-twelfth of the annual rent is incurred each month.
Payment liabilities: For obligations like workers’ compensation claims, tort settlements, and breach-of-contract damages, economic performance doesn’t happen until you actually make the payment.

That last category catches people off guard. You may owe a settlement for a fixed amount, but you can’t deduct it until the money changes hands.⁴

The Recurring Item Exception

Strict application of the economic performance rule would create headaches for routine costs that straddle year-end: utility bills, property taxes, insurance premiums that accrue in December but aren’t paid until January. The recurring item exception lets you treat these as incurred in the current tax year if economic performance follows shortly after, provided the fact of liability and a reasonably determinable amount exist by year-end, economic performance occurs by the earlier of the filing date (including extensions) or 8½ months after year-end, the liability recurs annually, and either the amount is immaterial or accruing it now better matches the related income.

The exception doesn’t cover everything. Interest, tort and workers’ compensation liabilities, and breach-of-contract obligations are excluded and still require actual payment.⁵

Prepaid Expenses and the 12-Month Rule

Paying in advance raises its own timing question. The general rule is that a prepaid cost is deductible only in the year the benefit applies. Pay a full year of insurance in November 2026, and only the November and December portion is deductible in 2026; the remaining ten months belong on your 2027 return.

The 12-month rule offers a shortcut for shorter prepayments. If the benefit doesn’t extend beyond the earlier of 12 months after it begins or the end of the following tax year, you can deduct the entire amount in the year you pay. A 12-month software subscription paid in July 2026 that runs through June 2027 qualifies. An 18-month service contract paid in July 2026 does not, because the benefit extends more than 12 months past the start date.²

Costs You Incur but Can’t Deduct Right Away

Not every cost you incur is a current-year deduction. If you buy something with a useful life longer than a single tax year, such as equipment, a building, or a vehicle, the cost is a capital expenditure. You recover it over the asset’s useful life through depreciation or amortization rather than deducting it all at once. A $50,000 piece of manufacturing equipment doesn’t reduce your taxable income by $50,000 in the year you buy it.

Inventory works the same way. The cost of goods purchased for resale is capitalized into inventory and doesn’t become deductible until the goods are sold, at which point it flows out as cost of goods sold. Under the uniform capitalization rules, both direct costs and certain indirect costs like warehousing and freight get folded into inventory basis instead of being deducted currently.²

Everyday Examples

Utility usage is the clearest case. Your household runs the air conditioning all through August, consuming electricity every hour. The utility company doesn’t bill until September, but the cost was incurred in August, when the power was actually used. An accrual-basis business’s August financial statements should reflect that cost even without an invoice in hand.

Employee wages behave the same way. The obligation to pay a worker begins the moment they start their shift, not when the paycheck is issued. Under federal law, all time an employee is required to be on duty or at a prescribed workplace counts as compensable work time.⁶ An employee who works 40 hours at $25 per hour during the last week of the month generates a $1,000 wage expense that week, even if payday is in the following month.

Loan interest is less obvious. Interest accrues daily on the outstanding principal. Payments may be due quarterly, but the cost builds continuously, and each month’s portion should be reflected in that month’s records for an accrual-basis taxpayer.

Records That Prove When You Incurred It

Proving when an expense was incurred matters as much as proving it existed. If the IRS challenges a deduction, you need documentation showing the economic event happened in the year you claimed it. The IRS expects records identifying the payee, the amount, the date the expense was incurred, and a description of what was purchased or received.⁷

For incurred-but-unpaid costs, bank statements alone won’t do it. Contracts, purchase orders, delivery receipts, and time logs establish the timing of the economic event. A signed delivery receipt dated December 15 proves property was received in December even if payment didn’t go out until February.

Getting the timing wrong cuts both ways. Claiming a deduction too early, before economic performance, can lead to the IRS disallowing it and assessing additional tax. Missing the correct year can also create problems, since the regulations generally prevent shifting an expense to a later return when it should have been taken earlier.³

1
Internal Revenue Service. Rev. Proc. 2025-32
2
Internal Revenue Service. Publication 538, Accounting Periods and Methods
3
eCFR. 26 CFR 1.461-1 – General Rule for Taxable Year of Deduction
4
eCFR. 26 CFR 1.461-4 – Economic Performance
5
eCFR. 26 CFR 1.461-5 – Recurring Item Exception
6
U.S. Department of Labor. Fact Sheet #22: Hours Worked Under the Fair Labor Standards Act (FLSA)
7
Internal Revenue Service. What Kind of Records Should I Keep