The main purpose of this section is to protect the safety of the goods. In the following two cases, the customs usually impose seals:

1. Customs open-box inspection. Customs inspection means that the customs officers open the containers or take out all of them for inspection, so as not to let the cargo owner think that they were illegally inspected by others, and seal a Customs seal to indicate that they were inspected by the Customs. At the same time, the seal number of the Customs must be recorded on the inspection record of the Customs.

2. Customs transfer. Customs transfer is the transfer of goods imported from the port customs to the inland customs declaration.

For example, the equipment imported from Xinjiang for West-to-East Gas Transport is imported from Tianjin Port. Then the customs officers of Tianjin Customs need to seal it with the seal of the Customs, indicating that the contents of the container have not been taxed and no one is allowed to dismantle it. Only after the customs declaration and tax payment in Urumqi can the demolition be carried out. If there are 16 pieces of equipment in the container, they need to pay 160,000 yuan tax. If five pieces are taken out halfway, the Urumqi Customs has been passive in checking the customs seal, which will cause trouble to the anti-smuggling police.

3. According to the Customs Law of the People's Republic of China:

Article 37 Goods under Customs supervision shall not be opened, extracted, delivered, shipped, exchanged, refitted, mortgaged, pledged, retained, transferred, replaced with markers, transferred for other purposes or otherwise disposed of without Customs permission. No one may open or destroy the seals imposed by the Customs without authorization.

Lead seal is a lock-like device applied by a specific person after the goods are loaded into the container and the door of the container is properly closed. Lead seals can be divided into customs seals, commodity inspection seals and commercial seals according to the different personnel. Once the lead seal is properly locked, it can not be opened unless it is severed by violence, and the damaged lead seal can not be reused. Each lead seal has a unique number. As long as the appearance of the container is complete, the door of the container is closed correctly and the lead seal is sealed properly, it can be proved that the container has not been opened privately in the course of transportation, and the situation in the container is supervised and responsible by the loader when loading the container. Customs seals are not allowed to be opened at will and should bear legal responsibility.