B.2 Good collection practices and comparison of data sources for transport
11.7. Enterprise/establishment surveys of resident and non-resident carriers are the main source for collecting transport services data in many cases. Compilers are advised to make sure that the survey is elaborate enough to cover most EBOPS categories related to transport services. An additional difficulty, which applies to all sources for transport, is obtaining the information necessary for compiling data on the basis on BOP recording rules. Compilers should also be aware of potential difficulties in obtaining data that reflects the activities of non-resident carriers for freight-related services (i.e., imports of freight transport services-debits). However, in many cases, transport operators establish branches or agents in client countries, which may then respond to surveys. For economies with regulated modes of transport, air transportation being the best example, this may even be more relevant. Alternatively, countries can survey resident importers and exporters about their transport expenditures paid both to resident and non-resident carriers.
11.8. Information on passenger transport services can also be obtained from traveller surveys, including by means of questions on passenger fares for international transportation, although the same limitations encountered in travel would apply, namely, the capacity of the respondent to provide the correct information, and the compiler’s knowledge of the population.
11.9. An ITRS may cover most exports and imports of transport services categories, but may not properly distinguish freight exports under FOB contracts where the transporter is a resident, or imports of freight transport under CIF contracts, as the transport value is usually included in the value of merchandise. In such cases, compilers need additional information to estimate the imports of freight transport services. In addition, when using ITRS, compilers should be aware that the country of operations may be different from the country of registration or residence of the owners, especially in marine shipping.
11.10. Administrative records, such as customs documents, could provide useful information for modelling freight costs, as long as they include information about the commodity traded, the weight, the origin and destination and the mode of transport. Obviously, including such information also depends on whether it is available for the carrier involved. For example, administrative records may not have information on transport costs by type of merchandise. They also will not be helpful for the transport of cargo or passengers from one foreign country to another by a resident transporter, and administrative records might also be a weak source for measuring transactions related to auxiliary transport services, such as loading containers, storage or air traffic control.
Next: B.3 Good collection practices and comparison of data sources for travel
 The reason for this is that, in line with BPM6 recommendations (para 10.78), all freight costs up to the customs frontier of the economy of the exporter are shown as incurred by the exporter and all freight costs beyond the customs frontier of the exporter are shown as incurred by the importer (see chapter 14 and BPM6 Compilation Guide, para. 12.35).