Cash Method of Accounting: Who Qualifies, Timing, and Switching

The cash method of accounting records income in the year you actually or constructively receive it and expenses in the year you pay them, tying your taxable income to your real cash flow rather than to invoices sent or bills owed. For tax years beginning in 2026, any business with average annual gross receipts of $32 million or less over the three prior tax years can use it, and individuals, sole proprietors, S-corporations, and most partnerships can use it regardless of size.¹

Who Qualifies

The eligibility rule sits in Section 448 of the Internal Revenue Code. A business passes the gross receipts test when its three-year average stays at or below the inflation-adjusted ceiling, which is $32 million for 2026.¹ The statutory base amount is $25 million, adjusted upward each year for cost of living.²

Section 448 only restricts C-corporations and partnerships that have a C-corporation as a partner. Sole proprietorships, S-corporations, and partnerships without a C-corporation partner fall outside the limitation entirely, so they can use the cash method no matter how much revenue they bring in.²

Aggregation of Related Businesses

Owning multiple companies does not let you slice your revenue into smaller pieces. When entities form a controlled group, the IRS combines their gross receipts for the $32 million test. That includes a parent that owns more than 50 percent of a subsidiary, brother-sister companies where the same small group of owners holds at least 80 percent of each, and affiliated service groups performing related work even without formal common ownership.³

Qualified Personal Service Corporations

Some professional C-corporations get a blanket pass on the gross receipts limit. If substantially all of the corporation’s work is in health, law, engineering, architecture, accounting, actuarial science, performing arts, or consulting, and substantially all of the stock is owned by employees performing those services, retired employees, or their estates, the company can use the cash method at any revenue level.²

When Income Counts as Received

You report income in the year you actually receive it or constructively receive it. Money is constructively received once it is credited to your account, set apart for you, or otherwise made available so you could draw on it, provided your control is not subject to substantial limitations or restrictions.⁴

The rule bites hardest at year-end. A check sitting in your mailbox on December 31 is that year’s income even if you deposit it in January. An electronic payment notification showing funds available for transfer does the same. You cannot defer income by waiting to collect money already within reach.

Deposits Versus Advance Payments

Money a customer pays you before you deliver goods or services is taxed based on who controls it. If you have an express obligation to return the money and the customer can demand it back, the payment is a deposit and is not income until you earn it. If you have no obligation to refund it and can use it however you want, it is an advance payment taxable in the year of receipt. The question is whether you have complete dominion over the funds.

When You Can Deduct an Expense

You deduct a business expense in the tax year you actually pay it.⁵ Timing turns on when you give up control of the money. A check mailed to a vendor on December 30 is deductible that year, regardless of when the vendor deposits it. Credit card purchases work in your favor here: the deduction lands when you make the charge, not when you pay the credit card bill, because the card issuer has already paid the vendor.

The 12-Month Rule on Prepaid Expenses

Cash-method taxpayers sometimes pay in advance for things like insurance or rent. You can deduct a prepaid amount in full in the year of payment as long as the benefit does not extend beyond the earlier of 12 months after it begins or the end of the following tax year.⁵ Pay a 12-month insurance premium on July 1, 2026, for coverage through June 30, 2027, and the whole premium is deductible in 2026. An 18-month policy running through December 2027 fails the test, and you spread the deduction across the years the coverage applies.

Prepaid Interest

Interest is the exception. Prepaid interest never accelerates the deduction. You allocate it across the tax years it covers and deduct only the portion attributable to each year.⁶ The 12-month rule does not apply.

Who Cannot Use the Cash Method

Tax shelters are always barred from the cash method, with no gross receipts escape.²
C-corporations, and partnerships with a C-corporation partner, whose three-year average gross receipts exceed $32 million must use accrual accounting.¹
Businesses for which producing or selling merchandise is a significant income source generally must use accrual methods for purchases and sales, unless they meet the Section 448(c) gross receipts test.⁵

The Small Business Inventory Exception

The old requirement that any merchandise seller use accrual accounting for inventory was loosened starting in 2018. Under Section 471(c), a business meeting the $32 million gross receipts test can skip traditional inventory accounting. You either treat inventory as non-incidental materials and supplies, deducting the cost when you use or sell the items, or follow whatever inventory method appears on your financial statements.⁷ Most small retailers and manufacturers can stay on the cash method through this exception. Tax shelters cannot.

Changing Your Accounting Method

Switching to or from the cash method requires IRS consent. You cannot just start reporting differently next year. You file Form 3115, Application for Change in Accounting Method, during the tax year the change takes effect.⁸

The Section 481(a) Adjustment

A method change can leave some items uncounted or counted twice during the transition. The Section 481(a) adjustment is a single number that captures the cumulative difference between the old and new methods.⁹ If it increases your income, you spread it evenly over four tax years starting with the year of change. If it decreases your income, you take the full benefit in the first year.¹⁰ The four-year spread matters when switching from cash to accrual, because recognizing years of outstanding receivables all at once can produce a crushing tax bill.

Automatic and Non-Automatic Consent

Most small businesses qualify for automatic consent. You attach one copy of Form 3115 to your timely filed return for the year of change and send a signed duplicate to the IRS office in Ogden, Utah, by mail or fax. No user fee applies.¹¹

Non-automatic changes apply when your situation does not fit one of the IRS’s pre-approved categories. They go through a formal review, require a user fee, can take months, and the IRS may impose conditions before granting consent.

What Happens if You Change Without Permission

Switching methods without filing Form 3115 is a costly mistake. The IRS can force you back to your old method and impose the Section 481(a) adjustment entirely in a single year rather than over four, often producing a much larger bill. Examiners can apply the reversal in the year of the unauthorized change or, if that year’s statute of limitations has closed, in the earliest open year.¹⁰ An examiner has discretion to bless the change after the fact, but that is the exception. Taxpayers who follow the process almost always end up with better terms than those caught skipping it.

1
Internal Revenue Service. Rev. Proc. 2025-32
2
Office of the Law Revision Counsel. 26 USC 448
3
Internal Revenue Service. FAQs Regarding the Aggregation Rules Under Section 448(c)(2)
4
eCFR. 26 CFR 1.451-2
5
Internal Revenue Service. Publication 538 – Accounting Periods and Methods
6
Internal Revenue Service. Topic No. 505 – Interest Expense
7
Office of the Law Revision Counsel. 26 USC 471
8
Internal Revenue Service. About Form 3115
9
Internal Revenue Service. Form 3115
10
Internal Revenue Service. 4.11.6 Changes in Accounting Methods
11
Internal Revenue Service. Instructions for Form 3115