Inappropriate use of antimicrobials in humans is a primary driver of antimicrobial resistance (AMR) emergence and spread. In 2020, WHO launched GLASS antimicrobial use (GLASS AMU), previously called GLASS AMC, to monitor the quantity and types of antimicrobial s us ed at the national and global levels. WHO invites Countries, Areas, and Territories (CTAs) to enrol in GLASS AMU and commit to building or strengthening their national AMU surveillance system and, when ready, to reporting their national AMU data. Data calls are opened every year.