Regardless of taxable income, every US-based domestic corporation must file tax Form 1120.
The following entities fall under the obligation to file tax Form 1120:
- Businesses opting for corporate taxation. These businesses must also complete Form 8832 and include a copy of Form 1120.
- Limited liability companies (LLCs). LLCs file Form 1120 only if they've chosen corporate taxation. Partnership LLCs use Form 1065, while single-member LLCs typically file taxes through the owner's personal federal tax return.
- Farming corporations. They are required to file Form 1120 to report their income/losses.
- Corporations with an ownership interest in a FASIT (Financial Asset Securitization Investment Trust).
- Foreign-owned domestic disregarded entities. If a foreign entity owns 100 percent of a domestic disregarded entity (D.E.), the D.E. is treated as separate from its foreign owner. The foreign entity must file Form 1120 and attach Form 5472.
Additionally, some types of corporations may need to complete additional forms, such as Form 1120 (Schedule N), for foreign operations in the U.S. Small corporations might not be required to fill out these additional forms. You can locate them by searching for "Form 1120" using the IRS Forms and Publications tool.