An LLP’s federal income tax return is due on the 15th day of the third month after its tax year ends. For a calendar-year LLP, that means March 15. Because March 15, 2026 falls on a Sunday, the LLP income tax return due date for the 2025 tax year shifts to Monday, March 16, 2026.1Office of the Law Revision Counsel. 26 USC 6072 – Time for Filing Income Tax Returns Miss it without an extension and the IRS charges $255 per partner for every month the return is late, up to twelve months.2Internal Revenue Service. Failure to File Penalty
An LLP files Form 1065, a pass-through information return. The partnership itself owes no federal income tax; profits and losses flow through to the partners, who report their share on their own returns.3Internal Revenue Service. About Form 1065, U.S. Return of Partnership Income No payment accompanies Form 1065, but the filing deadline still bites.
Calendar Year vs. Fiscal Year
The March 15 date applies to LLPs on a calendar year, which is most of them. The March deadline sits a full month ahead of the April 15 individual filing date so partners can receive their Schedule K-1 and use it to complete their Form 1040. In 2026 the individual deadline is Wednesday, April 15.4Internal Revenue Service. IRS Opens 2026 Filing Season
An LLP on a fiscal year uses the same formula: the 15th day of the third month after the fiscal year closes. A partnership with a June 30 year-end therefore files by September 15.1Office of the Law Revision Counsel. 26 USC 6072 – Time for Filing Income Tax Returns Partnerships cannot pick their tax year freely. The IRS generally requires the partnership to match the tax year of the partners holding a majority interest, and absent that, a year that produces the least aggregate deferral among partners.5eCFR. 26 CFR 1.706-1 – Taxable Years of Partner and Partnership Most LLPs with individual partners end up on the calendar year for that reason.
When any of these dates falls on a Saturday, Sunday, or legal holiday, the deadline rolls to the next business day.
Getting an Extension With Form 7004
An LLP that cannot file on time can request an automatic six-month extension by filing Form 7004.6Internal Revenue Service. About Form 7004, Application for Automatic Extension of Time To File Certain Business Income Tax, Information, and Other Returns For a calendar-year LLP filing for 2025, that pushes the return from March 16, 2026 to September 15, 2026. Form 7004 must reach the IRS on or before the original due date; a late Form 7004 is not a valid extension.
The form asks for the partnership’s legal name, address, EIN, tax year, and the return code for a partnership return.7Internal Revenue Service. Instructions for Form 7004 Because a partnership owes no entity-level tax, there is generally no payment to send with the extension. Check the EIN against IRS records before submitting; a mismatch is a common reason extensions get rejected.
An extension for the partnership does not extend any partner’s individual April 15 deadline. If the LLP takes the full six months, partners may need to file their own Form 4868 extension or estimate their partnership income to file on time.
Schedule K-1 Deadlines
Every partner must receive a Schedule K-1 showing their share of income, deductions, and credits, and the partnership files copies with the IRS alongside Form 1065.3Internal Revenue Service. About Form 1065, U.S. Return of Partnership Income The K-1 distribution deadline tracks the Form 1065 deadline, and extending the partnership return extends the K-1 deadline with it.
Failing to furnish correct K-1 statements to partners on time carries its own penalty under IRC §6722, with a base rate of $250 per statement.8eCFR. 26 CFR 301.6722-1 – Failure to Furnish Correct Payee Statements That penalty is separate from and stacks on top of the partnership-level late filing penalty.
What a Late Return Costs
Under IRC §6698, a late Form 1065 costs a flat dollar amount per partner for each month or partial month the return is late, capped at 12 months.9Office of the Law Revision Counsel. 26 U.S. Code 6698 – Failure to File Partnership Return The amount is adjusted for inflation and stands at $255 per partner per month for returns due in 2026.2Internal Revenue Service. Failure to File Penalty
A five-partner LLP filing three months late owes $3,825 (255 × 5 × 3). The same partnership at the 12-month ceiling owes $15,300. The penalty applies even if the LLP had no income and no partner owed tax on the flow-through.
An incomplete return can trigger the same charge. A Form 1065 filed on time but missing partner identifying details or required schedules is treated the same as one never filed.
Reducing or Removing the Penalty
Several routes exist for cutting a late-filing penalty, and the right one depends on the partnership’s size and history.
Small Partnership Exception
Revenue Procedure 84-35 lets the IRS presume reasonable cause and waive the penalty when the LLP meets all of the following:
- Ten or fewer partners, counting a married couple filing jointly as one partner.
- All partners are natural persons (not corporations, trusts, or other entities), other than a nonresident alien.
- Each partner’s share of every partnership item is the same proportion.
- Every partner reported their share of partnership income on a timely filed individual return.
An LLP that qualifies can respond to the penalty notice with a signed statement asserting eligibility under Rev. Proc. 84-35.10Internal Revenue Service. Understanding Your CP162B Notice The equal-allocation requirement is the sticking point: partnerships with unequal ownership percentages are out.
First-Time Abate
An LLP that doesn’t qualify for the small partnership exception may still get administrative relief through First-Time Abate. The partnership must have filed the same type of return for the three prior tax years, taken no penalties during those years (or had any prior penalty removed for an acceptable reason), and be current on all filing and payment obligations.11Internal Revenue Service. Administrative Penalty Relief No disaster or hardship narrative is required.
Reasonable Cause
Failing those, the LLP can argue reasonable cause on the facts. The IRS considers natural disasters, serious illness, inability to access records, and system failures that blocked timely electronic filing.12Internal Revenue Service. Penalty Relief for Reasonable Cause The partnership has to show it exercised ordinary care and still could not file on time. Forgetting the date, being too busy, or blaming a preparer generally will not carry a reasonable cause claim.
State Returns Are Separate
Most states with an income tax also require a partnership-level information return, and many align with the federal March 15 date. Some do not, and some states impose a minimum franchise tax or annual fee on LLPs regardless of income. Confirm the return date and any entity-level payment with the state tax authority where the LLP is registered or does business.