Tax Year 2020 Calendar Filed Corporate Income Tax Returns Due
Tax Year 2020 Corporate Income Tax returns are due for calendar filers on May 17, 2021.
- File and pay using an approved corporate income tax software provider,
- Pay taxes using Business Tax Express,
- Make ACH Credit Payments, or
- Use the Montana Corporate Income Tax Return (Form CIT).
If you have no business activity during the tax year, you may file an Affidavit of Inactivity for Corporations, Partnerships and Disregarded Entities (Form INA-CT).
See the Montana Form CIT Corporate Income Tax Booklet for more details on filing Corporate Income Tax.