As knowledge developed on trafficking of children for sexual purposes, a range of different terms emerged around the world to describe the phenomenon. Confusion and inconsistency in the use of terms, as well as the existence of diverging definitions and interpretations of key issues has contributed to inaccuracy and imprecision in data. This hinders actions to generate clear evidence and reduce the harmful effects for the victims. In 2016, a global Interagency Working Group, established at the initiative of ECPAT International and composed of representatives from UN agencies, child rights NGOs, and law enforcement agencies, developed and endorsed the “Terminology Guidelines for the Protection of Children from Sexual Exploitation and Sexual Abuse” (hereinafter “Luxembourg Guidelines”). The Luxembourg Guidelines are available online in English, French, Spanish, German, and Turkish and continue to be adapted into further languages to become increasingly available to child protection professionals all over the world. Although the Luxembourg Guidelines broadly and systematically identify, analyse and define a wide range of best/common terms that should be used to describe sexual exploitation of children and its manifestations, this paper only discusses terminology considerations on trafficking of children for sexual purposes.