He made his first full international appearance in 2010, by refereeing the 2009 Junior World Championship in Japan. His debut was between England and Barbarians in the 2010 mid-year tests. During the 2010 end-of-year tests he was touch judge for the Ireland v Samoa match, one of his high-profile appointments of the year. During the 2014 Autumn Internationals Garces took charge of the Cook Cup match between Australia and England at Twickenham. Garces won notable praise from both coaches due to the high level of fitness he showed in the match.