Tax crimes negatively affect all countries, developed and developing alike. They obstruct governments’ ability to collect revenue and undermine trust in the legal and financial system which can lead to a wide range of adverse outcomes. Tax crime is often closely linked to other forms of serious domestic and transnational crime, such as money laundering, corruption, the trafficking of drugs or people, and terrorist financing. This report sets out the rationale for adopting a national strategy for countering tax crime and to support jurisdictions’ efforts in designing such strategies, drawing from the practices of members of the OECD’s Task Force on Tax Crimes and other Crimes (TFTC).