C.R.S. § 5-16-102

(1) This article 16 shall apply to any collection agency, solicitor, or debt collector that has a place of business located: (a) Within this state; (b) Outside this state and collects or attempts to collect from consumers who reside within this state for a creditor with a place of business located within this state; (c) Outside this state and regularly collects or attempts to collect from consumers who reside within this state for a creditor with a place of business located outside this state; or (d) Outside this state and solicits or attempts to solicit debts for collection from a creditor with a place of business located within this state.