Yes, the formal way is to stamp the money and date. But if the company name and time are not stamped on the official seal, it still has legal effect. Article 490 of the Civil Code If the parties conclude a contract in the form of a contract, the contract is established when the parties sign, seal or press their fingerprints. Before signing, sealing or fingerprinting, one party has fulfilled its main obligations, and the contract is established when the other party accepts it.