Is it illegal for others to pretend to be couriers?

Yes

Pretending to be a courier is fraud. "Fraudulent use of other people's identity information to pretend to be someone else's courier is legally fraudulent." Lawyer Wang Wei of Liaoning Anxing Law Firm said that according to Article 266 of the Criminal Law, if the amount of fraud reaches more than 2,000 yuan, it can constitute a crime and will be investigated for criminal responsibility. However, fraudulent express delivery that does not reach a certain amount is a violation of the Public Security Administration Punishment Law.

According to Article 49 of the Law on Public Security Administration Punishment: Anyone who steals, swindles, plunders, robs, extorts or intentionally damages public or private property shall be detained for more than 5 days 10 days, and may also be fined for less than 500 yuan; If the circumstances are serious, he shall be detained for more than 10 and less than 15, and may also be fined less than 1000 yuan.

In this process, the courier company should also bear certain civil compensation.