What are the procedures for property management bidding? There are three methods of property management bidding: public bidding, invitational bidding and negotiated bidding. According to Article 10 of the Bidding and Bidding Law, bidding is divided into public bidding and invitational bidding. Public bidding means that the tenderer invites unspecified legal persons or other organizations to bid in the form of a bidding announcement. Invitation to bid means that the tenderer invites specific legal persons or other organizations to bid in the form of a bid invitation letter.