In principle, the informal sector is included in the national accounts framework, and some countries make special adjustments to include it in their national accounts estimations. However, due to lack of source data, it is sometimes misestimated. Information on whether the informal sector (and more generally, the non-observed economy) is included in national accounts statistics can be retrieved from metadata collected by the IMF available on their Dissemination Standards Bulletin Board (DSBB).

A publication by the United Nations Economic Commission for Europe (UNECE), Non-Observed Economy in National Accounts, presents an inventory of practices of 29 UNECE member countries in measuring non-observed economic activities (underground, illegal, informal, or undertaken by households for their final use).

In 2002 the OECD/IMF/ILO/CIS Stat issued a manual on measuring the non-observed economy, and the IMF also offers information in its General Data Dissemination System.