It's just a courtesy. Totally normal.

If it's a bribe, you know.

Unit bribery crime

Article 389 Whoever gives money or property to a state functionary in order to seek illegitimate interests is guilty of bribery.

In economic exchanges, those who, in violation of state regulations, give state functionaries property in a relatively large amount, or those who, in violation of state regulations, give state functionaries kickbacks or service fees in various names, shall be punished as bribery.

It is not a bribe to give property to a state functionary because of extortion without obtaining illegitimate benefits.

Article 390 Whoever commits the crime of accepting bribes shall be sentenced to fixed-term imprisonment of not more than five years or criminal detention; Whoever seeks illegitimate interests by bribery, if the circumstances are serious or cause heavy losses to the interests of the state, shall be sentenced to fixed-term imprisonment of not less than five years but not more than ten years; If the circumstances are especially serious, he shall be sentenced to fixed-term imprisonment of not less than 10 years or life imprisonment, and may also have his property confiscated.

If a briber voluntarily confesses to taking bribes before being prosecuted, the punishment may be mitigated or exempted.

Article 391 Whoever gives money or property to a state organ, a state-owned company, an enterprise, a public institution or a people's organization for the purpose of seeking illegitimate interests, or who, in economic exchanges, violates state regulations and gives kickbacks or service fees in various names, shall be sentenced to fixed-term imprisonment of not more than three years or criminal detention.

If a unit commits the crime mentioned in the preceding paragraph, it shall be fined, and the directly responsible person in charge and other directly responsible personnel shall be punished in accordance with the provisions of the preceding paragraph.

crime of introducing bribery

Article 392 Whoever introduces bribes to state functionaries, if the circumstances are serious, shall be sentenced to fixed-term imprisonment of not more than three years or criminal detention.

If a briber voluntarily introduces a bribe before being prosecuted, the punishment shall be mitigated or exempted.

Unit bribery crime

Article 393 Where a unit pays bribes for illegitimate interests, or violates state regulations by giving kickbacks or handling fees to state functionaries, if the circumstances are serious, it shall be fined, and the persons who are directly in charge and other persons who are directly responsible for it shall be sentenced to fixed-term imprisonment of not more than five years or criminal detention. If the illegal gains from bribery are owned by individuals, they shall be convicted and punished in accordance with the provisions of Articles 389 and 390 of this Law.

Article 394 State functionaries who accept gifts in domestic official activities or foreign exchanges shall hand them in according to state regulations, and shall not hand them in. If the amount is relatively large, he shall be convicted and punished in accordance with the provisions of Articles 382 and 383 of this Law.