Collusion between bidding units or between bidding units and tendering units to defraud the bid is collusion in bidding, which is a kind of speculation, and its root is the lack of integrity in the field of engineering construction and even the whole society.

Make sure that cross-bidding is not determined by the difference of quotation.

The way to identify string tags is as follows

1. The bidding documents are exactly the same, such as the same format, the same font and the same table color.

2. In the bidding documents, the mistakes are consistent.

3. In electronic bidding, the IP addresses registered by different bidders are the same, or the IP addresses are in a specific area.

4. The bidding documents of different bidders shall be compiled by the same computer or printed by the same auxiliary equipment.

5. The binding form, thickness and cover of the bidding documents are similar or even the same.

6. The bidding documents of one bidder are bound together with the documents of another bidder's name, such as the signature of the legal representative or authorized agent of another bidder and the official seal of another bidder.

7. The bidder's representative doesn't know the telephone number of the person in charge of the company.

8. The bidder's representative's hand trembled when signing, and the name signed was inconsistent with the name on the business card.

9. Different bidders sat in the same car before the bid opening, talking and laughing, but pretended not to know each other at the bid opening site.

10. The total bid price of different bidders is unusually consistent, or extremely different, or changes regularly.

1 1. The total bidding amount of different bidders is similar, but the itemized quotation is unreasonable and there is no reasonable explanation.

12. The winning bidder intentionally cancels or abandons the bid or fails to sign a contract with the tenderer as required without justifiable reasons.

13. Deliberately making invalid bidding documents according to the invalid bidding clauses in the bidding documents.

14. After the bidder has registered for three or more times in one year and purchased the bidding documents, it will no longer submit the bidding documents or attend the bid opening meeting.

15. Before the deadline for submission of bid documents, several bidders issued statements to withdraw their bid documents almost at the same time.

16. The bid bonds of different bidders shall be paid through the same account.

17. Multiple bidders use the bid guarantee issued by the same person or enterprise.

18. The after-sales service terms are the same.

19. Deliberately omitting the signature of the legal representative.

20. In the bidding documents submitted by several bidders, the legal representative is signed by the same person.