Understanding the increasingly complex structures of international trade is an important concern for policy makers, as deepening economic integration is characterised by the growing trade in intermediate goods and services between countries. Analyses based on international input-output tables can help address trade-related policy issues as well as providing other insights into the socio-economic and environmental impacts of globalisation. To link national input-output tables in order to carry out interdependent analyses across countries requires a consistent set of harmonised international bilateral trade data that ideally reflects recent output by the economic activities in question. This paper discusses the challenges faced when attempting to construct appropriate bilateral trade matrices using annual data collected by the OECD and United Nations, as well as national sources. While the main focus is on the increasing presence of "re-exports" in reported exports of goods data, this paper also addresses some other statistical and data issues that need to be considered, such as treatment of confidential (or "unallocated") trade in goods; trade in secondhand goods, scrap metal and other waste; differences in trade statistics across international statistical agencies; and the additional problems encountered when converting product-based trade data to industry-based classifications. Issues concerning Balance of Payments data, the main source for trade in services, are also addressed.