For further information see Colorado's W-9 (PDF) : . Colorado's Business Information Requests (PDF) : . Colorado Business and Licensing Department's Business Information Request Form (PDF) : Colorado W-9 (In-house Form) (PDF) : Colorado W-9 (Regents' W-9) and Other Information (PDF) : Request For Taxpayer Identification Number and Certification (PDF) : For further information see Colorado: How to Order a W-9 (PDF) ; Colorado Business & License Requests, W-9 (In-House Form) (PDF) and Other Information (PDF), Colorado's Business Form W-9 and Other Tax Information. If you experience difficulties using these forms, please contact us at: infocoloradobserver.com. Information on Colorado's Business Tax System can be found at All state taxes imposed are the responsibility of the government to whom they are paid. The business, educational, professional and religious tax codes of Colorado prohibit the use of any portion of these tax codes on income produced on the outside of the State by any taxpayer. Certain types of non-economic compensation may be treated as “work” and not “salary.” See, §6-1-103.5. The business, educational, professional and religious tax codes of Colorado provide specific penalties that may apply to any taxpayer who violates the rules of the respective tax codes or who fails or refuses to file a return. For more information about the tax codes or filing a return, please contact the Tax Commission.