Can property and security be in joint bid? Is it legal?

What you want to ask is "Is it legal for property companies and security companies to form a consortium to bid?" This behavior is legal.

According to official website, the database of national laws and regulations, Article 31 of the Bidding Law of People's Republic of China (PRC) stipulates that two or more legal persons or other organizations may form a consortium to jointly bid as a bidder, but each party shall have the corresponding ability to undertake the bidding project.

Therefore, the property company and the security company can form a bidding consortium to participate in the project subject to tender according to law, but both parties should sign a * * * agreement with the tenderee, clearly stipulate the corresponding work and responsibilities that both parties should undertake, and submit them to the tenderee as one of the contents of the response documents to prevent the lack of responsibilities or mutual shirking in the process of project performance, which makes it difficult to continue to perform the contract.