Legal analysis: it depends on the actual situation. Sometimes signature or seal is a selective relationship, that is to say, either signature or seal or both can be used at the same time. These three situations have the same significance for the establishment of the contract. Sometimes the requirement is signature, that is to say, the signature and seal are parallel, and only when the signature and seal are available can the agreement take effect.

Legal basis: Article 7 of People's Republic of China (PRC) Bill Law stipulates that the signature on a bill is signature, seal or both.

The signature of the legal person or other organization that uses the bill shall be the signature of the legal person or other organization plus the signature of its legal representative or its authorized agent. The signature on a bill of exchange shall be the real name of the party concerned. According to the nature of signature, it can be divided into legal person signature and natural person signature. Signature of legal person: generally, official documents are only stamped with the corporate seal (official seal) at the end of the official document; Some official documents involving the responsibility of the legal representative must have the name and official seal of the unit, as well as the signature and private seal of the legal representative.

The signature of a natural person shall be personally signed in the name column of the document, and the private seal of the party concerned shall be affixed.