What it is. The income tax return for a domestic C corporation. Unlike a partnership, the corporation pays the tax itself, at 21% federally. In fund land you meet it through blocker corporations, portfolio companies, and US corporate subsidiaries of foreign groups.
Who has to file. Every domestic corporation, whether or not it owes tax or had any income that year, unless it is a specific type with its own form (a REIT files 1120-REIT, an S corporation 1120-S, a foreign corporation 1120-F).
When it's due. The 15th day of the 4th month after year-end, so April 15 for a calendar-year company, with an automatic six-month extension to October 15 via Form 7004. The extension is for the paperwork only: tax still has to be paid by the original date.
Worked example
A Delaware blocker receives $10m of income from a fund's K-1. It files Form 1120, pays about $2.1m of federal tax, and later pays a dividend to its foreign owner out of what is left.
Where you'll see it: Blocker compliance, portfolio-company tax provisions, and due diligence on a target's filing history.
Full explainer: Schedule M-1 and M-3 book-to-tax adjustments →
See all 53 terms in the glossary
This glossary is general information, simplified for learning. It is not tax, legal or investment advice, and real structures turn on facts and documents not shown here.