Where to file your taxes for Form 1120-S ; A foreign country or U.S. possession. Corporations file Schedule M-3 (Form 1120) to answer questions about their financial statements and reconcile financial statement net income (loss)Form 1120-W, Estimated Tax for Corporations. Keep for corporation's records. This site provides efile information for corporations that prepare and transmit their own electronic corporate income tax returns. Yes. Certificates of formation can be filed online through SOSDirect 24 hours a day, 7 days a week. Use the chart to determine where to file Form 7004 based on the tax form you complete. Filing requirements.