Where to file your taxes for Form 1120-S ; A foreign country or U.S. possession. If the corporation's principal business, office, or agency is located in: Use the following IRS center address: the United States, Department of the TreasuryCorporate income tax filers use form TC-20. Subsidiary Corporations. Addresses for forms beginning with the number 1 ; Form 1120-W, Estimated Tax for Corporations. Keep for corporation's records. Want to incorporate in Utah? Learn how to structure your business, file the required documents, choose a name, and more. What tax form(s) does an Utah corporation need to file?