The Customs-Trade Partnership Against Terrorism (C-TPAT) is a voluntary public-private supply chain security initiative. C-TPAT members – including importers, carriers, consolidators, licensed customs brokers, and manufacturers – voluntarily adhere to cargo security standards in exchange for a range of benefits, such as reduced CBP inspections and priority border processing.
C-TPAT Mutual Recognition (MR) Arrangements facilitate bilateral trade by extending reciprocal recognition to qualifying foreign customs programs, thereby enabling members of the foreign programs to receive the benefits of C-TPAT membership. MR Arrangements indicate that security requirements, standards, and verification procedures of foreign industry partnership programs are substantially equivalent to those of C-TPAT.
CBP currently has MR Arrangements with only five countries: Canada, Japan, Jordan, New Zealand, and South Korea. These five countries have accounted for about 20 percent of US trade since 2004.
CBP has indicated that it is committed to growing the number of C-TPAT MR Arrangements. In December 2010, at a Transatlantic Economic Council meeting, US and EU officials discussed the possibility of implementing a MR Arrangement between the United States and the European Union by October 31, 2011.
In a June 2011 report, the US Chamber of Commerce called for CBP to develop a MR Arrangement with Mexico.
You can read up more in the fact file on USCBP Mutual Recognition Agreements and for a non-US perspective, you will find an excellent essay on Mutual Recognition of AEOs which I found on the World Customs Journal website.