Notwithstanding legislation, such as The Horse Passports Regulations 2009, in England, which requires all horses and ponies to have an identification document, or ‘passport’, racehorses in Britain have needed such as document for decades. Indeed, historically, racehorses were identified on racecourses by checking their colour and markings against those recorded on an outline drawing in their passports.
However, since 1999, every thoroughbred foal registered in Britain has had a uniquely-numbered microchip implanted in its neck. Nowadays, all racehorses are identified by scanning their microchips on entry to racecourse stables and, although passport checks are carried out on certain horses – including those making their racecourse debut – the passport is typically only used for identification purposes if the microchip cannot be read. In a worst-case scenario, if a horse cannot be identified by its microchip or its passport, it will be prevented from running.