Tefre, who starts for Førde IL, took part in junior races and FIS races from 2010 to 2014 . He was Norwegian junior champion with the relay in March 2012 . At the beginning of the 2014/15 season he made his debut in the Scandinavian Cup in Lillehammer and finished 22nd in the 15 km freestyle and ninth place in the sprint. In December 2015 he started the World Cup in Lillehammer for the first time and achieved 49th place in the skiathlon . In the 2016/17 season he came in ninth place in the overall ranking of the Scandinavian Cup with four top ten finishes. At the beginning of March 2018 in Lahti he scored his first World Cup points in his second World Cup participation with 14th place in the sprint. After finishing 51st in the Lillehammer Triple at the beginning of the 2018/19 season, he finished in the top ten four times in the Scandinavian Cup. He won the sprint in Madona and reached sixth place in the overall standings and fourth place in the sprint standings at the end of the season. In the 2019/20 season he won the overall ranking of the Scandinavian Cup with four top ten finishes, including third place over 15 km freestyle in Vuokatti . He also achieved his first podium finish in the World Cup in Planica with second place together with Håvard Solås Taugbøl in the team sprint.