Business Income Tax
Any corporation, partnership, joint venture, common trust fund, limited association, pool or working agreement, limited liability company or any other combination of persons or interests, that is required to file a federal income tax return, must file a Colorado Income Tax Return. An organization will be deemed to be doing business in Colorado if it is engaged in any activities in Colorado which are beyond the protection afforded by Public Law 86-272.
An organization doing business only in Colorado will compute its tax on 100% of the Colorado taxable income. However, an organization doing business in more than one state must apportion its taxable income to any states in which the corporation is doing business.
Business income tax returns are due by the fifteenth day of the fourth month after the end of your tax year, or by April 15 for traditional calendar year filers. If you are unable to file by your prescribed due date, you may file under extension. This is an extension of time to file, not to pay.