Your new partnership agreement says the tax year ends December 31. Your two partners file their personal returns on a June 30 fiscal year. One of those choices is about to lose — and it is probably the one in the agreement.
Pass-through entities do not get to pick a tax year the way a C corporation does. Congress decided in 1986 that letting partnerships choose freely was letting their owners defer tax for up to eleven months, so it chained the entity's year to the owners' years. Partnerships run a three-test gauntlet — the majority-interest test, the principal-partner test, and the least-aggregate-deferral test — while S corporations and personal service corporations are pinned to the calendar year with only narrow exits. Here is how each rule works, what happens when ownership changes the answer mid-stream, and the one election that buys you a different year-end anyway.
Why the Rule Exists: The Deferral Game
Before the Tax Reform Act of 1986, a partnership could adopt any fiscal year. So partnerships routinely adopted January 31 year-ends: eleven months of partnership income earned from February through December would not flow onto the partners' calendar-year returns until the following April — a year of interest-free deferral on the tax, every year, forever.
Congress closed that door with Section 706(b). The required-tax-year rules are all engineered around one idea: the entity's year must track the owners' years closely enough that deferral stays small. Every test below is just a different way of measuring "close enough."
Partnerships: The Three Tests in Order
Section 706(b) gives partnerships a strict hierarchy. Run test 1; if it produces an answer, stop. Otherwise run test 2, then test 3. You do not get to pick your favorite result.
Test 1: The Majority-Interest Taxable Year
If partners holding more than 50 percent of both partnership profits and capital all use the same taxable year, the partnership must use that year. That shared year is called the majority-interest taxable year.
Two details trip people up:
- It is profits and capital. A partner who owns 60 percent of the profits but only 40 percent of the capital does not count toward the majority. Both interests must clear 50 percent in aggregate for the group sharing the year.
- It is measured on testing days. The rule looks at ownership on the first day of the partnership's taxable year (and, under the regulations, each day the ownership structure could produce a different answer). A mid-year ownership change can flip the required year for the following year — more on that below.
In practice, most small partnerships have all-calendar-year individual partners, so test 1 resolves immediately: the partnership uses the calendar year. The fun starts when partners have different years.
Test 2: The Principal-Partners Test
If no majority-interest year exists, look at the principal partners — everyone holding 5 percent or more of profits or capital. If all principal partners share the same taxable year, the partnership uses it.
This test helps partnerships where ownership is fragmented across years but the significant partners happen to align. Suppose no group sharing one year clears 50 percent of both profits and capital — because, say, large profit shares sit with partners holding small capital stakes — yet every partner at or above the 5 percent line files on June 30. Test 1 fails, test 2 fires, and the partnership uses June 30. The test only works when all principal partners share one year, which makes it a narrow window — but it saves a test-3 calculation when it hits.
Test 3: Least Aggregate Deferral
When both tests fail, the partnership must compute the year-end that produces the least aggregate deferral of income to the partners. This is the test people dread, but the mechanics are just weighted arithmetic:
- List each partner's year-end as a candidate for the partnership's year-end.
- For each candidate, count the months of deferral from that year-end forward to each partner's own year-end. A partner whose year ends in the same month gets zero; a partner whose year ends later gets the number of months between the two.
- Weight each partner's months by that partner's profit share and add them up. That sum is the candidate's aggregate deferral.
- The candidate with the lowest sum wins.
A quick example: Adams (40 percent, August 31 year-end) and Baker (60 percent, December 31 year-end) form a partnership. No majority year exists (neither group clears 50 percent of both interests on a shared year — each is alone in their year), and the two principal partners disagree, so test 3 applies.
- Test August 31: Adams defers 0 months × 0.40 = 0. Baker defers 4 months (September through December) × 0.60 = 2.4. Aggregate: 2.4.
- Test December 31: Adams defers 8 months (January through August) × 0.40 = 3.2. Baker defers 0 × 0.60 = 0. Aggregate: 3.2.
August 31 produces the smaller number, so the partnership's required year ends August 31.
One mercy rule: if the winning candidate beats the partnership's current year by less than 0.5, the current year stands (the de minimis rule in Regulation 1.706-1). Ownership churn does not force a year change over rounding dust.
S Corporations and PSCs: Calendar Year, With Two Exits
S corporations live under Section 1378, which is blunter than the partnership rules: the required year is the calendar year, full stop. The same goes for personal service corporations under Section 441(i). There are exactly two ways out.
Exit 1: Business Purpose (Including the Natural Business Year)
The IRS will approve a different year if the corporation establishes a business purpose — and the regulations deem one specific fact pattern to be a purpose automatically: the natural business year. If 25 percent or more of the corporation's gross receipts for a 12-month period land in its final two months, for three consecutive years, that period is a natural business year. The classic case is the retailer whose year ends January 31, after the holiday rush — closing the books when inventory is lowest and staff finally has time to count it.
Anything else requires a ruling request on Form 1128 showing genuine business reasons. "Our shareholders would prefer to defer income" is, to put it mildly, not one.
Exit 2: The Section 444 Election
Section 444 lets a partnership, S corporation, or PSC elect a year-end with a deferral period of three months or less — no business purpose required. For an entity whose required year is the calendar year, that means exactly three choices: September 30, October 31, or November 30.
The election is made on Form 8716, and the price of admission is the Section 7519 required payment: each year the entity deposits with the IRS an amount approximating the tax its owners defer by using the fiscal year, computed on Form 8752. Think of it as a security deposit on the deferral — it neutralizes the government's cost of letting you keep the odd year-end, and it is refunded or credited when the election ends. Miss the required payment and the election terminates, dropping you back onto the required year.
Section 444 is popular with seasonal businesses — a ski lodge or a holiday retailer that wants its year to end in the slow season — and with accounting firms themselves, which famously cluster on September 30 year-ends so their own busy season does not collide with tax season.
When Ownership Changes the Answer
The required year is not set once at formation. If a new partner's admission, a buyout, or a profit reallocation produces a different majority-interest year, the partnership must change to it — generally for the taxable year following the change. A calendar-year partnership that admits a June-30 fiscal-year partner holding 60 percent of profits and capital will find its required year is now June 30.
Year changes go through Form 1128, and the good news is that a change to a required year generally qualifies for automatic consent under the revenue procedures (no ruling fee, no months of waiting). The short year created by the switch gets its own return, and income may need annualizing. This is one of those moments where clean monthly books pay for themselves: reconstructing an August 31 close from a shoebox in February is how deadlines get missed.
Tracking It in Your Books
Whatever year the rules hand you, your bookkeeping has to honor it: closing entries, adjusting entries, and comparative reports all key off the fiscal year-end, not December 31. In a plain-text ledger, that means your year-end close transaction carries the fiscal date, and interim statements cut at the right month.
A partnership on a required August 31 year-end, booking its Section 7519 required payment alongside the year-end close, might record:
2026-08-31 * "Year-end close - Section 7519 required payment deposited with Form 8752"
Assets:US:Bank:Checking -4,200.00 USD
Assets:Prepaid-Tax:Section-7519-Deposit 4,200.00 USD
2026-08-31 * "Close books - fiscal year ending August 31"
Equity:Current-Earnings -52,310.00 USD
Equity:Retained-Earnings 52,310.00 USDThe deposit is an asset, not an expense — it comes back when the Section 444 election ends — and parking it in its own account keeps the refund traceable years later. If you ever need to prove your deferral-period math or reconstruct a short year after an ownership change, per-month account balances in a tool with a visual dashboard make the archaeology far less painful; the Fava dashboard can slice any fiscal year into monthly columns without rebuilding your chart of accounts.
Common Mistakes to Avoid
- Assuming the operating agreement controls. The agreement can say whatever it wants; Section 706 overrides it. Review the required year every time ownership shifts.
- Counting only profits for the majority test. Capital counts too. A profits-only majority is not a majority.
- Electing Section 444 and forgetting Form 8752. The required payment is annual, and skipping it kills the election.
- Picking a fiscal year for a new S corporation without a purpose or election. The default is the calendar year. File Form 8716 on time or establish the natural business year — do not just start filing on June 30 and hope.
- Forgetting state conformity. Some states do not follow the federal required-year rules or the Section 444 election cleanly. Check yours before you assume one year works everywhere.
The One-Paragraph Version
Partnerships must use their majority owners' shared year if one exists, their principal partners' shared year if not, and the year-end with the least aggregate deferral otherwise. S corporations and personal service corporations must use the calendar year unless they prove a business purpose or make a Section 444 election for a September, October, or November year-end — paying an annual deposit for the privilege. Ownership changes can move the required year, and the fix is a Form 1128 change to the new one. Run the tests before you assume December 31; the penalty for guessing is a year of books closed on the wrong date.
