Form 1120 vs. Form 1065: Which Tax Return Does Your U.S. Business File?

"Which tax return does my business file?" is one of the most common questions we hear from new business owners. The answer depends on how your business is classified for federal tax purposes, which is not always the same as how it was formed with the state.

The short answer

Form 1065: the partnership return

Form 1065 is filed by partnerships and by LLCs with two or more members that have not chosen to be taxed as a corporation. A partnership generally does not pay federal income tax itself. Instead, its income, deductions, and credits "pass through" to the partners.

• Each partner receives a Schedule K-1 showing their share of the results, which they report on their own return.
• For calendar-year partnerships, Form 1065 is due March 15, with an extension to September 15 available through Form 7004.
• Partnerships must file even in a year with little or no activity, and late-filing penalties are charged per partner, per month.

Partnerships with foreign partners may have additional reporting and withholding obligations, so it is important to plan for these early.

Form 1120: the corporate return

Form 1120 is filed by C corporations, including LLCs that have elected to be taxed as corporations. A C corporation is a separate taxpayer:

• It pays federal corporate income tax on its profits at a flat rate of 21%.
• Profits paid out to shareholders as dividends may be taxed again at the shareholder level.
• For calendar-year corporations, Form 1120 is due April 15, with an extension to October 15 available through Form 7004.

Where does the foreign-owned single-member LLC fit?

A single-member LLC owned by a non-U.S. person is normally a "disregarded entity", so it does not file a regular Form 1120 or Form 1065. However, it must file Form 5472 attached to a pro forma Form 1120 to report transactions with its owner. It is a common source of confusion: the LLC uses the Form 1120 as a cover page, but it does not become a C corporation or pay corporate tax by doing so.

Can you choose how your business is taxed?

Yes, within limits. An LLC can elect to be taxed as a C corporation by filing Form 8832, or as an S corporation by filing Form 2553. Note that S corporations cannot have nonresident alien shareholders, so the S corporation option is generally not available to foreign owners.

The right choice depends on your profits, where you live, how you plan to take money out of the business, and your state's rules. It is worth getting advice before you elect, because changing classification later can be restricted.

Remember your state return

Your federal return is only part of the picture. Many states require their own partnership, corporate, or franchise tax filings, and deadlines and fees vary from state to state.

How Meritline Tax helps

We prepare Form 1065 with Schedules K-1 from $300, Form 1120 from $300, Form 5472 with pro forma Form 1120 starting from $200, and state returns from $100. If you are not sure which return your business files, a business structure consultation can confirm it before any deadline.

This article is general information based on federal rules as of October 8, 2026. It is not tax or legal advice for your specific situation. Rules and due dates can change, so confirm your requirements before you file.