The Estonian Classification of Economic Activities (EMTAK) is the national version of the international harmonised NACE classification. EMTAK has a hierarchical structure, being divided into five levels. The first four levels conform to the NACE structure and the fifth level is the national level, established according to the specifics of the Estonian economy and the relevant legislation.

EMTAK is the basis for determining the field of activities which in turn is an important source of statistics for various categories. Division into fields of activities improves also the international comparability within a category.