Calling airmail signature on behalf of invoicing failed because the system failed to dock, so it can be signed manually. Invoice refers to the business vouchers issued and collected by all units and individuals in buying and selling goods, providing or receiving services and engaging in other business activities, and is the original basis of accounting. Receipt is the proof of receipt and payment, and invoice can only prove that the business has happened, but can't prove whether the money has been received or paid.

Aviation signature is a kind of electronic seal technology, which can ensure the validity and timeliness of signature. Users can make electronic seals quickly and conveniently according to their own needs, and the protection of seals meets the requirements of relevant national laws and regulations, providing users with more convenience.

Classification of signatures

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.

Because modern seals are engraved by computer, the probability of being forged increases correspondingly, and the single seal of a seal is also a mere formality, so it is often combined with handwritten signature. With the improvement of modern fingerprint analysis ability, some important contracts should be stamped with handprints in addition to signatures and seals. The signature and seal at this time include signature, seal and handprint.