Retailers must file sales tax returns reporting all sales made, whether taxable or exempt, at regular intervals in accordance with prescribed filing schedules. Sales made by a charitable organization are exempt from sales tax if all three of the following conditions are met: See Department publication Sales & Use Tax Topics: Charitable Organizations for additional information regarding sales made by charitable organizations. If some part of real property is severed and removed, it once again becomes tangible personal property and may be subject to sales tax if sold. A lessor may submit a completed, Any retail sale that is made in Colorado is subject to, Colorado taxation. A retailer may be required to collect tax even if it has no physical presence in Colorado. If a retailer ceases to maintain any place of business in Colorado, the retailer may no longer be doing business in Colorado, depending on its other activities within Colorado, as described below in, Retailers with no physical location in Colorado. Colorado sales tax reference for quick access to due dates, contact info, and other tax details. [CDATA[/* >