Mexico requires import and export documentation including a completed "pedimento," or import/export form, for all commercial crossings. This document must be accompanied by a commercial invoice (in Spanish), a bill of lading, documents demonstrating guarantee of payment of additional duties for undervalued goods, if applicable, and documents demonstrating compliance with Mexican product safety and performance regulations, if applicable. The import documentation may be prepared and submitted by a licensed Mexican customs house broker or by an importer with sufficient experience in completing the documents.
For tax purposes, all Mexican importers must apply and be listed in the Official Register of Importers (Padrón de Importadores), maintained by the Secretariat of Treasury and Public Finance (SHCP). In addition, the Secretariat of Treasury and Public Finance maintains special sector registries. To be eligible to import more than 400 different items, including agricultural products, textiles, chemicals, electronics, and auto parts, Mexican importers must apply to the Secretariat of Treasury and Public Finance to be listed on these special industry sector registries.
Beginning in 2015, any Mexican importer in the Official Register of Importers can be in charge of all of their own import paperwork and compliance with Mexico's customs regulations. Use of a customs broker for import transactions is no longer a requirement. Mexican customs law is very strict regarding proper submission and preparation of customs documentation. Errors in paperwork can result in fines and even confiscation of merchandise as contraband. As a result, a customs broker’s services may still be needed for the import process. U.S. exporters are advised to ensure that Mexican clients employ competent, reputable Mexican importers or customs house brokers. Because customs brokers are subject to sanctions if they violate customs laws, some have been very restrictive in their interpretation of Mexican regulations and standards.
Source: US Department of Commerce