BUSINESS  TAX  INFORMATION

Business Tax Administration of the Chicago Department of Revenue has a staff specifically dedicated to assist Chicago business owners to understand and comply with all of the municipal tax ordinances in the City of Chicago.

Illinois Department of Revenue provides information on Illinois tax legislation and laws. Illinois tax publications, forms, and instructions

Internal Revenue Service provides information on tax publications, forms, and links to state forms. Current tax legislation and laws can be found here.

Internal Revenue Service, Information for Tax-Exempt Organizations provides information regarding the requirements for tax-exempt organizations, how to apply for recognition of tax-exempt status by the IRS, and the annual filing requirements for tax-exempt organizations.

Internal Revenue Service, Plain Language Regulations provides business regulations in Plain English. The IRS has summed it up so you don't have to deal with all the legal jargon.