Form 3115 Accounting Method Changes: When to Switch and How Section 481(a) Adjustments Work

An accounting method change is any change in the overall plan of accounting (cash to accrual, or vice versa) or a change in the treatment of a material item (such as how depreciation is calculated, when revenue is recognized, or how inventory is valued). Under IRC 446(e), a taxpayer may not change their method of accounting without the consent of the Secretary of the Treasury, obtained by filing Form 3115. The good news is that most common changes qualify for automatic consent under IRS Revenue Procedures, meaning the form is filed with the tax return and the change takes effect without waiting for IRS approval. The Section 481(a) adjustment is the mechanism that makes the transition clean: it calculates the cumulative difference between the old method and the new method as of the beginning of the year of change, and either adds that amount to income (positive adjustment, spread over 4 years) or allows it as a deduction (negative adjustment, taken in full in the year of change).

How do accounting method changes work?

What triggers a required change in accounting method?

The IRS requires a change in accounting method when your current method doesn’t clearly reflect income (IRC 446), when a C corporation (or a partnership with a C corporation partner) has gross receipts above the IRC 448 cash-method threshold ($32 million average for the prior 3 years, for tax years beginning in 2026), or when a new tax law mandates a different method. Voluntary changes (such as switching from cash to accrual to better match revenue and expenses) require filing Form 3115, with your tax return for automatic changes or with the IRS National Office during the year of change for non-automatic ones. Most accounting method changes require a Section 481(a) adjustment, which captures the cumulative difference between the old and new methods. A positive 481(a) adjustment (additional income) is spread over 4 years, while a negative adjustment (additional deduction) is taken entirely in the year of change. Changes made under the automatic consent procedures (Rev. Proc. 2015-13 for the procedures and Rev. Proc. 2025-23 for the list of automatic changes, or their successors) don’t need advance IRS approval but must follow detailed filing requirements.

Should I use cash basis or accrual basis accounting for my small business?

Cash basis records income when received and expenses when paid, making it simpler and giving you more control over timing. Accrual basis records income when earned and expenses when incurred, regardless of payment timing, providing a more accurate picture of profitability. The IRS requires accrual for businesses with inventory that have average annual gross receipts exceeding $32 million (for tax years beginning in 2026; $31 million for 2025). Below that threshold, you can choose either method. Most small service businesses use cash basis because of its simplicity and the ability to time income and deductions for tax planning. Once you choose a method, switching requires filing Form 3115 and may trigger a Section 481(a) adjustment; a positive one spreads over four years, while a negative one is taken all at once.

How often should a small business reconcile its accounts?

Monthly reconciliation is the minimum standard for any business, but weekly reconciliation catches errors faster and makes month-end closing significantly easier. Bank reconciliation compares your accounting records to bank statements to identify timing differences (outstanding checks, deposits in transit) and errors (duplicate entries, missed transactions). Credit card reconciliation should happen monthly at minimum, matching each statement charge to a recorded transaction with the correct expense category and ensuring no unauthorized charges slipped through. Businesses with high transaction volume (retail, restaurants, e-commerce) benefit from daily point-of-sale reconciliation, which catches discrepancies before they compound into material misstatements at year-end.

This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.