within 31 days

The time for signing the contract after bidding is within 31 days from the date of issuing the bid-winning notice. The tenderer and the winning bidder shall conclude a written contract in accordance with the tender documents and the bidding documents of the winning bidder, and shall not conclude other agreements that violate the substantive contents of the contract.

according to article 43 of the bidding law of the people's Republic of China, before the winning bidder is determined, the tenderer shall not negotiate with the bidder on the bid price, bidding scheme and other substantive contents. Forty-fifth after the winning bidder is determined, the tenderer shall issue a letter of acceptance to the winning bidder, and at the same time notify all bidders who have not won the bid. The bid-winning notice has legal effect on the tenderer and the winning bidder. After the bid-winning notice is issued, if the tenderer changes the bid-winning result, or if the winning bidder abandons the bid-winning project, it shall bear legal responsibility according to law. Article 46 A tenderer and a winning bidder shall conclude a written contract in accordance with the tender documents and the bid documents of the winning bidder within 31 days from the date of issuance of the bid-winning notice. The tenderer and the winning bidder shall not conclude any other agreement that deviates from the substantive contents of the contract. If the tender documents require the winning bidder to submit the performance bond, the winning bidder shall submit it.