What Is Form 3115 and When Does a Business Need to File One?
Sam's List Editorial | 2026-08-11
Form 3115 is the IRS Application for Change in Accounting Method. A business files it to get consent to change how it reports an item of income or expense for tax purposes, such as moving from cash to accrual, fixing a depreciation method, or changing how inventory costs are handled. Most changes require it even when the change is correcting something you have been doing wrong.
That last sentence is the part people find surprising, and it is where the form earns its reputation.
Why Consent Is Required at All
IRC section 446(e) says a taxpayer who wants to change an accounting method must get the consent of the Secretary. Not tell the IRS. Get consent.
The reason is arithmetic. An accounting method determines the timing of income and deductions, not the total. If you could switch methods freely, you could double count a deduction or drop income out entirely in the year of the switch.
Form 3115 is how the IRS gives that consent and how the timing is squared up.
Method Change Versus Error Correction
This is the distinction that decides which route you take, and business owners get it backward constantly.
A change in accounting method covers the overall method of accounting, such as cash or accrual, and the treatment of any material item that affects timing. Depreciating an asset over the wrong recovery period for two years is a method. Capitalizing something that should have been expensed, consistently, is a method.
An error is a mistake in applying the method: a math error, a transposed number, an item posted to the wrong year by accident, one time.
The rough test is repetition. A treatment applied consistently over two or more filed returns is generally a method, and methods are changed with Form 3115. A one-off mistake is generally corrected by amending the return.
Getting this wrong is costly in both directions. Amending returns to fix what is really a method change does not establish a new permissible method, and filing Form 3115 for something that was a simple error creates work you did not need.
Automatic Versus Non-Automatic Consent
There are two tracks.
Automatic consent applies to method changes the IRS has pre-approved and listed, currently in Rev. Proc. 2022-14 as updated. You file Form 3115 with the timely filed return for the year of change, including extensions, and send a copy to the IRS as instructed. There is no user fee, and consent is granted when you comply with the procedure.
Non-automatic consent applies to everything else. The application is filed during the year of change, not with the return, it carries a user fee, and the IRS reviews and rules on it individually.
Most small business changes fall in the automatic bucket. Check the current revenue procedure and its designated change numbers rather than assuming, because the list is revised regularly and a change that was automatic in a prior year may not be.
The Section 481(a) Adjustment
This is the mechanism that prevents duplication or omission when the method changes.
The section 481(a) adjustment is a catch-up calculation. It measures the cumulative difference between what your income would have been under the new method and what you actually reported under the old one, as if the new method had always applied.
The spread rules follow the direction:
| Adjustment | Effect | Timing |
|---|---|---|
| Negative (decreases income) | Taxpayer favorable | Generally taken entirely in the year of change |
| Positive (increases income) | Taxpayer unfavorable | Generally spread ratably over four years |
There is also a de minimis election allowing small positive adjustments to be taken in one year rather than spread, which is often simpler for a small business.
The four year spread is a real planning consideration. A method change that raises income by $80,000 lands as $20,000 a year rather than all at once, which can matter for bracket management and for anything driven by adjusted gross income.
Common Situations That Trigger Form 3115
- Cash to accrual, or accrual to cash. Growth past a gross receipts threshold forces the first. Qualifying under the small business exception in section 448(c) allows the second.
- Depreciation catch-up. An asset placed in service with the wrong class life or method, or missed bonus depreciation, is corrected by method change rather than by amending years of returns.
- Capitalization changes. Adopting or changing the treatment of repairs versus improvements under the tangible property regulations.
- Inventory and section 263A. Changing how indirect costs are allocated to inventory, or exiting UNICAP under the small business exception.
- Advance payments and deferral. Changing the timing of income recognition on prepayments under section 451.
Cost segregation studies on property owned for several years are the most common reason a real estate investor meets this form. The prior depreciation was a method, so the catch-up runs through Form 3115 rather than through amended returns.
What Filing Actually Involves
The form is not long, but the substantiation behind it is where the work sits. You need the present method described accurately, the proposed method, the designated change number if automatic, and the section 481(a) computation with support.
The computation is the part that requires care. It is a cumulative figure, sometimes reaching back many years, and it needs to be reproducible from records if anyone asks.
This is not a DIY form for most owners. The cost of professional preparation is usually small next to the timing benefit of getting a method change right, and considerably smaller than a failed change discovered later.
If you need someone to run it, compare accountants by specialty and client reviews in the Sam's List accountant directory.
Frequently Asked Questions
What is Form 3115 used for? It is the IRS Application for Change in Accounting Method, used to request consent to change an overall method of accounting or the tax treatment of a material item that affects timing. Common uses include switching between cash and accrual, correcting depreciation, and changing inventory or capitalization treatment.
Do I file Form 3115 or amend my return? If the treatment was applied consistently across two or more filed returns, it is generally a method and is changed with Form 3115. A one-time mistake in applying an otherwise correct method is generally fixed by amending the return. The distinction is technical, so confirm it with a tax professional.
What is a section 481(a) adjustment? It is the cumulative catch-up amount that prevents income from being duplicated or omitted when a method changes. Adjustments that decrease income are generally taken in full in the year of change, while adjustments that increase income are generally spread over four years, with a de minimis election available for small amounts.
Is there a fee to file Form 3115? Automatic consent changes carry no user fee and are filed with the timely filed return for the year of change, including extensions. Non-automatic changes are filed during the year of change and require a user fee, with the IRS reviewing each request individually.
About the author: Kimberly Green is the cofounder of Sam's List, where business owners and high earners find vetted CPAs, financial advisors, and fractional CFOs. She's met one-on-one with 400+ financial professionals and writes from the real data behind thousands of client-advisor matches. Ask her anything about finding an accountant - she's heard it all, including the questions people are afraid to ask.