The standard for filing a case is: 1. Damage to the legitimate interests of the tenderer, bidders or the state, collectives and citizens, resulting in direct economic losses of more than 500,000 yuan; 2. The amount of illegal income is more than 100,000 yuan; 3. The amount of the winning project is more than two million yuan; 4. Take threats, deception or bribery and other illegal means; 5. Although it does not meet the above-mentioned amount standard, it is also a collusive bidding behavior if it is subject to administrative punishment more than twice within two years; 6. Other serious circumstances.

Legal basis: Article 223 of the Criminal Law of People's Republic of China (PRC).

Bidders who collude with each other in bidding quotations and harm the interests of the tenderee or other bidders, if the circumstances are serious, shall be sentenced to fixed-term imprisonment of not more than three years or criminal detention and shall also or only be fined.

Bidders and tenderers who collude in bidding and harm the legitimate interests of the state, collectives and citizens shall be punished in accordance with the provisions of the preceding paragraph.

Provisions of the Ministry of Public Security of the Supreme People's Procuratorate on the standards for filing and prosecuting criminal cases under the jurisdiction of public security organs (2) Article 76.

Bidders collude with each other in bidding quotation, or bidders collude with the tenderee in bidding, which is suspected of one of the following circumstances, and shall be filed for prosecution:

(a) damage the legitimate interests of the tenderer, bidders or the state, collective and citizens, resulting in direct economic losses of more than 500 thousand yuan;

(two) the amount of illegal income is more than one hundred thousand yuan; (three) the amount of the winning project is more than two million yuan; (four) by threats, deception or bribery and other illegal means;

(five) although not up to the above standards, but within two years due to collusion, by more than two administrative penalties, and collusion;

(six) other serious circumstances.