Maine imposes an income tax on all entities organized as corporations and that have Maine-source income. The corporate income tax is graduated, with rates ranging from 3.5% (for income up to $350,000) to 8.93% (for income in excess of $3,500,000). The tax generally does not apply to S corporations unless the corporation has federal taxable income at the corporate level. The tax does not apply to financial institutions that are subject to Maine’s franchise tax, or to insurance companies subject to premiums tax.
Current Year (2022) Forms
These are forms due in 2023 for income earned in 2022.
Unitary Questionnaire (PDF) - Updated May 2023
Nexus Questionnaire (PDF) - Updated May 2023
- Rule 801 - Apportionment
- Rule 808 - Corporate Income Tax Nexus
- Rule 810 - Maine Unitary Business Taxable Income, Combined Reports and Tax Returns
P.O. Box 1060
Augusta, ME 04332-1060