The tax code is an identification number needed to open a bank account, to draw up a rental agreement or to purchase a mobile phone.
It is issued by the Agenzia delle Entrate, by presenting a valid Identity Document or a passport.

Local office of Agenzia delle Entrate
Corso Bolzano 30,
Torino
Tel: +39 0115523111
Web site: https://www.agenziaentrate.gov.it/wps/portal/english/