Itin, itín or ITIN may refer to Individual Taxpayer Identification Number, a United States tax processing number International Token Identification Number, a unique identifier of tokens build upon Blockchain technology Ilya Itin (born 1967), Russian concert pianist Vivian Itin (1894–1938), Russian writer Itín, Chaco, a village and municipality in northern Argentina Prosopis kuntzei, a South American leguminous tree known as itín Itin., abbreviation of itinerary or itinerarium