Legal analysis: required. According to the Bidding Law, the bidding documents must be sealed well and the official seal and legal person seal must be complete, otherwise the bid will be discarded. 1. Only signature without legal person seal is not enough, and it is not the signature of the legal person but the signature of the authorized person of the legal representative. 2. The official seal and legal person seal are not in the sealing area but in the bid. The cover or quotation inside the document.

Legal basis: "Tendering and Bidding Law of the People's Republic of China" Article 3 The following engineering construction projects within the territory of the People's Republic of China include the survey, design, construction, supervision and The procurement of important equipment, materials, etc. related to project construction must be subject to bidding:

(1) Large-scale infrastructure, public utilities and other projects related to social public interests and public safety;

(2) Projects that use state-owned capital investment or state financing in whole or in part;

(3) Projects that use loans or aid funds from international organizations or foreign governments.

The specific scope and scale standards of the projects listed in the preceding paragraph shall be formulated by the development planning department of the State Council in conjunction with relevant departments of the State Council and submitted to the State Council for approval.

If the law or the State Council has regulations on the scope of other projects that require bidding, those regulations shall prevail.