Sometimes referred to as a customs bureau or a bureau of customs, a customs agency is a government entity that is charged with the responsibility of overseeing and enforcing governmental laws relating to imported goods and services. Most countries around the world have a customs agency, often under the direction of the department that is responsible for managing national matters of finance.

While the exact processes and procedures utilized by a customs agency will vary slightly from one country to another, there are several basic functions that just about every customs department will provide. One of the central functions has to do with imports. A customs agency will handle the task of assessing and collecting the tariffs set on imported goods. This collection will follow customs regulations that have been put in place by the federal government of the country. Along with collections, customs personnel will also handle the imposition of any fines or penalties that may be applicable to the import process.

Another important role of a customs agency is identifying and minimizing the incidence of fraud and the smuggling of goods into the country. This will often involve controlling the entry points to the country, inspecting inbound shipments, and certifying that goods entering the country are doing so in keeping with all applicable laws and regulations. In some cases, this will also extend to working with postal officials to inspect packages and other forms of mail coming into the country from a foreign location.

Many countries extend a great deal of authority to a customs agency when it comes to the seizure of illegally imported goods. Officers of the customs agency are granted powers that are much like those of the internal law enforcement system, allowing them to make arrests, seize contraband, and begin the process of prosecuting individuals and companies that are attempting to introduce goods into the country illegally.

In the United States, the customs agency, better known as the Bureau of Customs, is under the direction of the Treasury Department. Customs agencies in other countries generally operate under the auspices of a larger department. However, there are a few instances where a customs agency functions as an independent entity with lateral ties to other pertinent departments and agencies within the national government.