Form 1128: How to Change Your Business Tax Year and Why It Matters

Most startups default to the calendar year without thinking about it. You incorporate in March, file your first return for the period ending December 31, and that becomes your tax year. It feels natural because most individual tax returns follow the same pattern.

But the calendar year is not always the right choice for every business, and in some situations the IRS requires a specific tax year regardless of what you would prefer. When your current tax year no longer fits your business, or when a structural change forces you to adopt a new one, the form you need is Form 1128.

This guide explains what Form 1128 is, who needs to file it, how the two tracks (automatic approval versus ruling request) work, what a short period return requires, and the mistakes that consistently delay or derail the process.

What is Form 1128?

Form 1128, officially titled "Application to Adopt, Change, or Retain a Tax Year," is the IRS form businesses use to request permission to change their annual accounting period. Section 442 of the Internal Revenue Code requires IRS approval before a business can adopt, change, or retain a tax year that differs from the required year.

Form 1128 is used to request a change in tax year, and to adopt or retain a certain tax year. Partnerships, S corporations, personal service corporations, and trusts may be required to file the form to adopt or retain a certain tax year.

The form covers three distinct situations. Adopting a tax year means selecting an annual accounting period for the first time when the entity would otherwise default to the calendar year but wants a different period. Changing a tax year means moving from the current accounting period to a new one. Retaining a tax year means asking the IRS to allow an entity to keep a tax year that has come under scrutiny or that would otherwise require a switch to the required year.

The current version of Form 1128 is dated October 2014, last updated on the IRS website March 31, 2026. The form itself has not changed significantly but the revenue procedures and user fees that govern it are updated periodically.

Who needs to file Form 1128?

You need Form 1128 when you are adopting a first tax year that requires consent, changing an existing year, retaining a year that now needs consent, or electing a 52-53 week year.

The entities that most commonly file Form 1128 are corporations (C-Corps and S-Corps), partnerships and multi-member LLCs, personal service corporations (PSCs), and trusts with EINs. Sole proprietors and single-member LLCs that are disregarded entities generally use the individual's tax year and do not file Form 1128.

There are situations where Form 1128 is not required. A newly formed C-Corp can adopt any tax year it chooses simply by filing its first return for that period, without needing prior IRS approval. A newly formed partnership or PSC that wants to adopt a tax year other than its required tax year must go through the ruling process, but a newly formed S-Corp is more restricted. A single-member LLC or sole proprietor who has not previously filed a tax return can adopt any tax year with the first filing.

Form 1128 becomes necessary when an existing entity wants to change from its current tax year to a different one, when a pass-through entity needs IRS consent to keep a non-required year, or when an entity involved in a merger or restructuring ends up with misaligned accounting periods.

Calendar year vs Fiscal year

Your tax year determines when your tax return is due, when estimated tax payments are scheduled, and how income and expenses are matched across periods. The choice between a calendar year and a fiscal year affects more than just the dates on your return.

A calendar year runs from January 1 to December 31. This is the default for most businesses and aligns with the tax year of most individual shareholders, which simplifies pass-through tax planning. Most US companies use the calendar year, and institutional investors, lenders, and financial statement users are accustomed to calendar-year financials.

A fiscal year is any 12-month period that ends on the last day of any month other than December, or a 52-53 week year that always ends on the same weekday nearest to the end of a particular month. Common fiscal year endings include June 30, September 30, and March 31. Retailers often prefer a January 31 fiscal year end because it captures the full holiday season in one period. Government contractors sometimes align with the federal government's September 30 fiscal year.

Why a startup might want a fiscal year:

Seasonal revenue concentration is the most legitimate reason to prefer a fiscal year. When most of a company's revenue arrives in one or two months, a calendar year can split a natural business cycle across two returns and distort the financial picture. A business that earns 60% of its annual revenue in November and December might prefer a fiscal year ending January 31 so that the peak season is captured in a single reporting period.

Alignment with a parent company or controlling shareholder is another reason. When a subsidiary joins a consolidated group, it may be required to adopt the parent's fiscal year to enable consolidated tax return filing.

Post-acquisition alignment is a common trigger. When a company is acquired, the new parent may require the acquired entity to change its accounting period to match the rest of the group. This is typically a non-automatic change that requires a ruling request.

Why most startups should stay on the calendar year:

For most early-stage startups with no dominant seasonal revenue pattern, the calendar year is the right choice. It aligns with investor expectations, simplifies financial reporting comparisons, reduces compliance complexity, and avoids the administrative burden of maintaining a fiscal year accounting system that is out of sync with vendors, employees, and service providers who all operate on a January-to-December basis.

Required tax years: When the IRS decides for you

Some entities do not have a free choice. The IRS prescribes a "required tax year" for certain entity types, and changing away from the required year requires a compelling business purpose and formal IRS approval.

S-Corporations are generally required to use the calendar year. An S-Corp can use a fiscal year only if it can demonstrate a natural business year using the 25-percent gross receipts test, if the fiscal year is an ownership tax year that matches the tax year of shareholders holding more than 50% of shares, or if it files a Section 444 election with Form 8716 to use a fiscal year with a required deferral period. Form 1128 is the vehicle for adopting or retaining a natural business year or ownership tax year.

Partnerships are generally required to use the tax year of their majority partners. If partners holding more than 50% of profits and capital share the same tax year, the partnership must use that year. If the majority partner test is not met, the partnership uses the tax year of all principal partners. If neither test produces a common year, the partnership defaults to the calendar year.

Personal service corporations are required to use the calendar year unless they can establish a natural business year using the 25-percent gross receipts test or elect a fiscal year under Section 444.

C-Corporations have the most flexibility. A C-Corp can adopt any tax year with its first return and can change that year with IRS consent, though the required tax year rules, the 48-month prior change bar, and the business purpose requirement all apply.

Automatic approval and ruling request

Form 1128 has two distinct procedural paths. Choosing the wrong one is one of the most expensive mistakes filers make.

Track 1: Automatic approval (Part II)

Use Part II for automatic approval if you meet a revenue procedure. Corporations generally look to Rev. Proc. 2006-45. Partnerships, S corporations, PSCs, and many trusts look to Rev. Proc. 2006-46.

The automatic approval track requires no user fee. You complete Part I and Part II of Form 1128, attach the required statements and financial data, and file the form with your regular IRS service center as an attachment to your short-period return. The envelope should be marked "Attention: Entity Control" at the top.

To qualify for automatic approval under Rev. Proc. 2006-45 (for corporations) or Rev. Proc. 2006-46 (for pass-through entities), you must satisfy all applicable conditions in the relevant revenue procedure. The most common conditions are that you are changing to a natural business year established by the 25-percent gross receipts test, changing to the required tax year for your entity type, or changing to an ownership tax year in the case of an S-Corp.

The 25-percent gross receipts test works as follows. You take your gross receipts for the last two months of the requested 12-month period and divide them by total gross receipts for the entire 12-month period. If this percentage is 25% or more in each of the three most recent 12-month periods ending in the requested month, you have established a natural business year. You need 47 months of gross receipts data to complete this calculation.

Track 2: Ruling request (Part III)

If you do not qualify for automatic approval, you file a ruling request under Part III. This is sent to the IRS National Office, Associate Chief Counsel, Income Tax and Accounting, at P.O. Box 7604, Ben Franklin Station, Washington, DC 20044-7604.

As of February 17, 2026, the user fee for a Form 1128 ruling request is typically $5,750, and $6,100 for certain Section 9100 relief extensions, paid through pay.gov.

The ruling request requires a full statement of facts, a description of your current and proposed tax year, the business purpose for the change, financial data demonstrating the purpose, and a discussion of why the change would not create a tax benefit that is the primary motivation for the request. The IRS has significant discretion in ruling requests and may approve, deny, or approve with conditions.

Ruling requests take considerably longer to process than automatic approval filings. Allow several months at minimum. Do not rely on a ruling request to implement a time-sensitive tax year change.

The user fee amounts are published in the annual IRS user fee revenue procedure, which for 2026 is Rev. Proc. 2026-1. Always confirm the current schedule on IRS.gov before submitting payment.

The 4 disqualifiers that block automatic approval

These are the conditions that push a filer from the free automatic track to the $5,750 ruling request track. Each one needs to be checked before assuming automatic approval applies.

The 48-month prior change bar: If the entity has changed its annual accounting period at any time within the most recent 48-month period ending with the last month of the requested tax year, automatic approval is not available. The 48-month period is measured precisely, and planning a tax year change requires confirming when the prior change was made and whether the 48-month window has expired.

There are exceptions to the 48-month bar. A change to a required tax year, a change from a 52-53 week year to a non-52-53 week year that ends with reference to the same calendar month (or vice versa), and certain changes by S-Corps or PSCs to comply with common tax year requirements do not count as prior changes for this purpose.

Open examination status: An entity that is currently under IRS examination, before an appeals office, or in federal court on any issue related to its annual accounting period generally cannot use the automatic approval procedures. Special consent from the IRS is required.

Entity-specific disqualifiers under Rev. Proc. 2006-45: Corporations face additional disqualifiers including having a required tax year (unless changing to it), being an S-Corp attempting to change to a non-permitted year, being a cooperative with a short-period loss, leaving a consolidated group, and having certain interests in pass-through entities or controlled foreign corporations at the end of the short period.

Failing the applicable test: For pass-through entities using Rev. Proc. 2006-46, if the requested year does not satisfy the 25-percent gross receipts test and is not the required year or an ownership tax year, automatic approval is not available.

The short period return: What it is and why it matters

Every tax year change creates a short period. The short period is the time between the end of your old tax year and the beginning of your new one. It is shorter than 12 months and requires its own separate tax return.

Here is how it works in practice. Suppose a corporation has a fiscal year ending August 31 and wants to change to a calendar year ending December 31. The corporation files a final return for its last full fiscal year (September 1 through August 31). It then files a short period return for September 1 through December 31. Starting the following January, it files calendar-year returns.

The short period return is not filed as part of the annual return. When a short year results from a change in accounting period, the IRS requires you to annualize taxable income. The purpose is to prevent bracket manipulation. Without annualization, a six-month return would push less income through the lower tax brackets and artificially reduce the effective rate.

Annualizing income for the short period works by multiplying the short period taxable income by 12 and dividing by the number of months in the short period. The resulting annualized income determines the tax rate. You then multiply by the ratio of short period months to 12 to get the actual tax owed for the short period. The calculation prevents a taxpayer from benefiting from compressed tax brackets simply by creating an artificially short tax year.

The short period return must be marked "Change in Accounting Period" at the top. Form 1128 requires you to identify your current year-end, the requested new year-end, and the business reason for the change. Filing Form 1128 late or incorrectly can result in the IRS rejecting the change entirely, which means the short-period return you filed may not be accepted.

You can request an extension for a short period return using Form 7004. The extension is generally six months. You do not need to annualize income in a short period created by a newly formed entity (one that was not required to use a 12-month period before), only in short periods created by a change in accounting period.

Form 1128 vs Form 3115

Form 3115 changes your accounting method. Form 1128 changes the tax-year period itself. The wrong form goes to the wrong IRS pipeline and the request comes back unprocessed.

These two forms are frequently confused by founders and occasionally by their advisors. The distinction is precise:

Form 1128 changes when your tax year begins and ends. The period itself shifts. A business going from a December 31 year-end to a September 30 year-end files Form 1128.

Form 3115 changes how you account for items within a tax year. A business switching from cash-basis to accrual-basis accounting files Form 3115. A business changing its depreciation method files Form 3115.

You can file both forms in connection with the same restructuring if the situation requires changes to both the period and the method, but they are filed separately, go to different IRS offices, and follow completely different procedures.

Similarly, Form 8716 (Election To Have a Tax Year Other Than a Required Tax Year) is distinct from Form 1128. Form 8716 is the Section 444 election that allows certain pass-through entities to use a fiscal year that defers income to shareholders by up to three months. Form 1128 is IRS consent to adopt or change a tax year. They serve different purposes, have different timing rules, and carry different consequences.

When and where to file Form 1128

For automatic approval requests:

For automatic approval, attach Form 1128 to the applicable return, usually the short-period return, and file at your normal IRS service center. Add "Attention, Entity Control" on top.

The filing deadline for an automatic approval request is the due date of the short-period return that implements the change, including extensions. For a corporation changing to a calendar year with a short period ending December 31, 2025, the Form 1128 must be attached to the short-period return and filed by April 15, 2026, or September 15, 2026 if a Form 7004 extension is filed.

Do not send a user fee with an automatic approval application. No fee is required for automatic approval. Sending a check with a Part II filing slows processing without providing any benefit.

For ruling requests (Part III):

File Form 1128 with the user fee with the IRS National Office before the end of the tax year for which the change is requested. For ruling requests, the form is filed before the short-period return, not attached to it. Mail to: Internal Revenue Service, Associate Chief Counsel (Income Tax and Accounting), Attention: CC:PA:LPD:DRU, P.O. Box 7604, Ben Franklin Station, Washington, DC 20044-7604.

No electronic filing option exists for Form 1128. The form is paper-only, submitted by mail to the applicable address depending on whether it is an automatic or ruling request.

Common mistakes that derail Form 1128 filings

Assuming automatic approval applies without checking the disqualifiers. The most expensive mistake. Filers who assume they qualify for automatic approval, skip the ruling request, and file Form 1128 under Part II only to discover they were disqualified by the 48-month bar or examination status end up with an invalid tax year change. The IRS may reject the short-period return, and the original tax year continues to apply. Correcting this typically requires a late Section 9100 relief request, which carries the $6,100 fee.

Confusing Form 1128 with Form 3115. Filing Form 3115 when Form 1128 is required, or vice versa, sends the application to the wrong IRS pipeline and results in the request being returned unprocessed. The entity's tax year does not change, and the filing deadlines for the short-period return may have passed by the time the error is discovered.

Filing the short-period return before the Form 1128 is processed. For automatic approval requests, Form 1128 is attached to the short-period return and filed simultaneously. For ruling requests, Form 1128 must be filed first and approved before the short-period return is submitted. Filing the return before the ruling is received for a non-automatic change can create a records mismatch that requires significant effort to untangle.

Failing to annualize income on the short-period return. Submitting a short-period return without annualizing taxable income is an error that can trigger IRS scrutiny and a notice requesting correction. The annualization calculation must be attached to the short-period return.

Missing the 47-month gross receipts data for the 25-percent test. The natural business year determination requires 47 months of gross receipts data. Many founders and advisors underestimate how much historical data the IRS requires and submit incomplete calculations that the IRS cannot verify.

Not marking the short-period return. A short-period return that is not clearly marked "Change in Accounting Period" at the top, and does not have Form 1128 attached (for automatic requests), will be processed as if it were an incomplete annual return.

What this means for India-US founders

For an Indian founder with a Delaware C-Corp and an Indian subsidiary, the tax year question has an additional dimension. The Indian subsidiary operates under India's Assessment Year framework, which runs from April 1 to March 31. The US parent's calendar year and the Indian subsidiary's April-to-March year create a natural mismatch in consolidated reporting.

This mismatch does not require a tax year change for the US entity. US GAAP consolidation handles the timing difference through appropriate cut-off procedures and the Form 5471 reporting framework. However, if the US parent wanted to align more closely with the Indian subsidiary's year, it could adopt a March 31 fiscal year through Form 1128. For most startups, this is not worth the administrative complexity, but for companies where the India subsidiary represents the majority of operations, year-end alignment can simplify the transfer pricing analysis and the Form 5471 preparation.

If a Delaware C-Corp is acquired by an Indian parent company with a different fiscal year, the acquiring parent may require the US subsidiary to adopt the same fiscal year for consolidated reporting. This type of post-acquisition alignment is a common trigger for a Form 1128 ruling request, since it is unlikely to qualify for automatic approval given the business purpose framing and the controlled group considerations involved.

If your startup needs to change its tax year, align with a parent company's accounting period, or evaluate whether a fiscal year makes sense for your business structure, book a demo with Inkle to work through the Form 1128 eligibility analysis, the short-period return preparation, and the filing strategy with a tax professional who handles cross-border and multi-entity structures.

Frequently Asked Questions

Does a new startup need to file Form 1128 to choose its tax year?

Generally no. A newly formed C-Corp can adopt any tax year by simply filing its first return for that period. Pass-through entities like S-Corps and partnerships have required tax years from the start and may need Form 1128 or a Section 444 election using Form 8716 to use a non-required year. Once a tax year is adopted through the first filing, changing it later always requires Form 1128 and IRS approval.

What is the user fee for Form 1128 in 2026?

Automatic approval requests filed under Part II have no user fee. If you qualify under Rev. Proc. 2006-45 or Rev. Proc. 2006-46, the filing is free. If you do not qualify and must file a ruling request under Part III, the fee as of February 17, 2026 is $5,750 for most requests and $6,100 for certain Section 9100 relief extensions, paid through pay.gov. Confirm the current amount before filing as fees are updated annually.

What is the 48-month prior change bar?

It is a rule that blocks automatic approval if your entity has already changed its annual accounting period within the most recent 48-month period ending with the last month of the requested tax year. If you changed your tax year less than 48 months ago, you must either wait out the window or file a Part III ruling request and pay the user fee. Changes to a required tax year and certain technical 52-53 week year adjustments are excepted from this bar.

What is a short period return and do I always need to file one when I change my tax year?

Yes, a short period return is always required when you change your tax year. It covers the gap between your old year-end and your new one, which is typically less than 12 months. Income on a short period return must be annualized to prevent the compressed period from reducing your effective tax rate artificially. You can extend the short period return deadline using Form 7004.

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