Colo. Code Regs. 39-26-117
Where any vendor sells his business he shall make a return and pay all taxes due within ten days of such sale. The purchaser of the business is liable for any unpaid tax due on sales made by his predecessor, including tax on outstanding accounts on which sales tax has not been remitted. The purchaser is required to withhold a sufficient amount of the purchase money to cover any taxes due and unpaid until the vendor can provide proof any such taxes have been paid.
Sales tax shall be remitted by the purchaser on the price paid for tangible personal property, other than inventory, acquired with the purchase of business and for use or consumption in the operation of the business. The tax shall be based on the price paid for such chattels as are recorded in the bill of sale or purchase agreement and which constitute part of the total transaction at the time of sale or transfer. Where the transfer of ownership is a "package deal" in a lump sum transaction the sales tax shall be based on the book value set up by the purchaser for income tax depreciation purposes or, if no such value is established, the fair market value.
39-26-117