Barry George Frost grew up on a dairy farm near Leigh, north of Auckland. He went to school at Mahurangi College in Warkworth before moving to Auckland for work. After playing club cricket in Auckland, he retired from the senior ranks and transitioned into officiating during the 1995-96 season.
His career on the field quickly progressed. Frost made his List A umpiring debut in 1998 and stood in his first first-class match the following year. Over his career, he went on to umpire 102 first-class matches and 94 List A games, officiating through the end of the 2015-16 season.
Frost also made his mark on the international stage. He umpired three men's Twenty20 Internationals between 2010 and 2012. He was also heavily involved in the women's international game, officiating 10 women's One-Day Internationals between 1997 and 2015, alongside eight women's Twenty20 Internationals between 2010 and 2015.
Away from the boundary rope, Frost helped shape the profession for his peers by serving as the founding President of the New Zealand Professional Cricket Umpires' Association in 2011. During his final season in 2015-16, he became only the eighth New Zealand umpire to officiate in 100 first-class matches.