The merchandise trade data have been compiled by national statistical authorities largely complying with the United Nations recommended International Merchandise Trade Statistics, Concepts and Definitions 2010 (IMTS 2010).^[1] The main elements of the concepts and definitions are:

1. Coverage: As a general guideline, international merchandise trade statistics should record all goods that add to or subtract from a country’s stock of material resources by entering (imports) or leaving (exports) its economic territory. The general guideline is subject to the clarifications provided in IMTS 2010, particularly the specific guidelines in Chapter 1 concerning the inclusion or exclusion of specific categories of goods.
2. Time of recording of transactions: As a general guideline, it is recommended that goods be recorded at the time when they enter or leave the economic territory of a country.
3. Statistical territory: The statistical territory of a country is the territory for which trade statistics are being compiled. The definition of the statistical territory may or may not coincide with the economic territory of a country or its customs territory, depending on the availability of data sources and other considerations. It follows that when the statistical territory of a country and its economic territory differ, international merchandise trade statistics do not provide a complete record of inward and outward flows of goods.
4. Trade systems: Depending on what parts of the economic territory are included in the statistical territory, the trade data-compilation system adopted by a country (its trade system) may be referred to as general or special.
   • The general trade system is used when the statistical territory coincides with the economic territory. Consequently, it is recommended that the statistical territory of a country applying the general trade system comprises all applicable territorial elements. In this case, imports include goods entering the free circulation area, premises for inward processing, industrial free zones, premises for customs warehousing or commercial free zones, and exports include goods leaving those territorial elements;
   • The special trade system is in use when the statistical territory comprises only a particular part of the economic territory, so that certain flows of goods which are in the scope of IMTS 2010 are not included in either import or export statistics of the compiling country. The strict definition of the special trade system is in use when the statistical territory comprises only the free circulation area, that is, the part within which goods “may be disposed of without customs restriction”. Consequently, in such a case, imports include only goods entering the free circulation area of a compiling country and exports include only goods leaving the free circulation area of a compiling country.
   • The relaxed definition of the special trade system is in use when (a) goods that enter a country for, or leave it after, inward processing, as well as (b) goods that enter or leave an industrial free zone, are also recorded, and included in international merchandise trade statistics.
5. Classifications: It is recommended that countries use the Harmonized Commodity Description and Coding System (HS) for the collection, compilation, and dissemination of international merchandise trade statistics as suggested by the Statistical Commission at its twenty-seventh session (22 February to 3 March 1993).^[2] The Harmonized System was adopted by the Customs Co-operation Council in June 1983, and the International Convention on the Harmonized System (HS Convention) entered into force on 1 January 1988 (HS 1988).^[3] In accordance with the preamble to the HS Convention, which recognized the importance of ensuring that the HS be kept up to date in the light of changes in technology or in patterns of international trade, the HS is regularly reviewed and revised. The sixth edition, HS 2017, came into effect 1 January 2017.^[4] The Standard International Trade Classification (SITC)^[5], which was in the past used by countries in data compilation and reporting, has been recognized for its continued use in analysis.^[6]
6. Valuation:  At its fifteenth session in 1953, the Economic and Social Council, taking the view that trade statistics must reflect economic realities, recommended that the Governments of Member States of the United Nations, wherever possible, use transaction values in the compilation of their national statistics of external trade or, when national practices are based on other values, endeavour to provide supplementary statistical data based on transaction values (Economic and Social Council resolution 469 B (XV)). To promote the comparability of international merchandise trade statistics and taking into account the commercial and data reporting practices of the majority of countries, it is recommended that: (a) The statistical value of imported goods be a CIF-type value; (b) The statistical value of exported goods be an FOB-type value; however, countries are encouraged to compile FOB-type value of imported goods as supplementary information. FOB-type values include the transaction value of the goods and the value of services performed to deliver goods to the border of the exporting country. CIF-type values include the transaction value of the goods, the value of services performed to deliver goods to the border of the exporting country and the value of the services performed to deliver the goods from the border of the exporting country to the border of the importing country.
7. Partner country:  It is recommended that in the case of imports, the country of origin be recorded and that in the case of exports, the country of last known destination be recorded. The country of origin of a good (for imports) is determined by rules of origin established by each country. The country of last known destination is the last country – as far as it is known at the time of exportation – to which goods are to be delivered, irrespective of where they have been initially dispatched to and whether or not, on their way to that last country, they are subject to any commercial transactions or other operations which change their legal status. Further, it is recommended that country of consignment be recorded for imports as the second partner country attribution, alongside country of origin; the compilation of export statistics on the country of consignment basis is only encouraged, depending on a country’s needs and circumstances.

For more detailed information on national practices in the compilation and dissemination of international merchandise trade statistics, please go to website of IMTS National Compilation and Dissemination Practices Survey