The Export and Import Price Index (XMPI), which are compiled on quarterly bases, covers both exports and imports of merchandise trade. These quarterly specification-based XMPI have been compiled and disseminated since the first quarter of 2013 up to the last quarter 2017 with reference base period being the quarter ending March 2013. The updated XMPI has the fourth quarter of 2017 as the reference base period. The updated weights and the product sample for the XMPI used customs data for the years 2014 to 2016. Price collection for the updated XMPI was carried out during the period October-December 2017. This allowed for the compilation of the XMPI for the fourth quarter of 2017 using the new product and enterprise samples.