Is it necessary to invite tenders for the third-party fire detection of subway construction below 500,000 yuan? What is the basis of the document? It is best to have official documents as the basis.

According to the National Development and Reform Commission's Standard Provisions on Bidding Scope and Scale of Engineering Construction Projects, if the estimated price of a single contract is more than 500,000 yuan, public bidding must be conducted for the procurement of services such as subway engineering survey, design and supervision. Therefore, those under 500,000 can be exempted from bidding. Whether to adopt public bidding depends on whether the local owner has other internal regulations.