Form 1065 deadline: when partnerships and multi-member LLCs file

A calendar-year partnership generally files Form 1065 by the 15th day of the third month after year-end. In 2026, March 15 falls on Sunday, so a calendar-year 2025 partnership return is due March 16, 2026. The partnership generally provides Schedule K-1 to each partner on the same timetable.

A domestic LLC with two or more members is generally classified as a partnership for federal income-tax purposes unless it elects to be treated as a corporation. That means an entity formed as an LLC under state law can still have a Form 1065 filing obligation.

Form 7004 is used to request the automatic filing extension for Form 1065. The IRS tax calendar states that the extension is six months. Partner-level estimated taxes and other payments have their own deadlines; the partnership extension does not automatically extend an owner's personal obligations.

Before tax preparation, reconcile partner contributions, distributions, guaranteed payments, loans, and ownership changes. A partnership can have perfectly reconciled bank accounts and still produce a difficult return if the capital and partner-level activity are not supported.

Partnership accounting needs a clean record of who contributed cash or property, who received distributions, how partner loans were handled, and when ownership or profit-sharing arrangements changed. Keep those records with the legal agreements and accounting schedules that support them.

Before the tax handoff, reconcile the balance sheet and partner-level activity, identify intercompany or related-party transactions, and document unusual items that may need tax judgment. The return preparer should not have to infer ownership changes from bank transfers or rebuild capital activity from email.

After filing, retain the Form 1065, K-1 support, extension and payment records where applicable, and any adjustments that need to flow back into the books. Partner and state obligations should remain on their own calendars.