The government procurement contract is signed between the purchaser and the winning bidder, not between the purchaser and the branch of the winning bidder. During the performance of the contract, it cannot be performed by the head office. The main body of signing and fulfilling the procurement contract is the winning company (branch), not the head office.
According to article 46 of People's Republic of China (PRC) government procurement law
The purchaser and the supplier who has won the bid and clinched the deal shall, within 30 days from the date of issuing the notice of winning the bid and clinching the deal, sign the government procurement contract according to the matters determined in the procurement documents.
The bid-winning notice has legal effect on both the purchaser and the bid-winning supplier. If the purchaser changes the bid-winning or transaction result after the bid-winning or transaction notice is issued, or if the bid-winning or transaction supplier abandons the bid-winning or transaction project, it shall bear legal responsibility according to law.
Extended data:
Relevant provisions of the Government Procurement Law of People's Republic of China (PRC).
The purchaser and the supplier who has won the bid and clinched the deal shall, within 30 days from the date of issuing the notice of winning the bid and clinching the deal, sign the government procurement contract according to the matters determined in the procurement documents.
The bid-winning notice has legal effect on both the purchaser and the bid-winning supplier. If the purchaser changes the bid-winning or transaction result after the bid-winning or transaction notice is issued, or if the bid-winning or transaction supplier abandons the bid-winning or transaction project, it shall bear legal responsibility according to law.
The purchaser and procurement agency shall properly keep the procurement documents of each procurement activity of government procurement projects, and shall not forge, alter, conceal or destroy them. The storage period of procurement documents shall be at least fifteen years from the date of completion of procurement.
Baidu Encyclopedia-People's Republic of China (PRC) Procurement Law