What Address Goes on Form 1120? Principal Office vs Mailing Address Explained
Key Takeaways
- Use principal office address, not registered agent address
- IRS explicitly prohibits registered agent address as business address
- Use C/O formatting for reliable U.S. mail delivery
- Keep addresses consistent across forms
Principal Office vs Mailing Address
The Form 1120 address should be your principal office or place of business — not the registered agent's address. The IRS instructions explicitly prohibit using the registered agent address.
C/O Address for Foreign Owners
If your principal office is overseas, use C/O formatting to route mail through a reliable U.S. third party: C/O [Third Party Name], [Their Address]. Keep addresses consistent between Form 1120 and Form 5472 Part I.
IRS Form 1120 Instructions
Official IRS source on irs.gov
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