 After signing for Esbjerg in his native Denmark, he joined Huddersfield Town in 2013 on a youth contract.Billing signed a four-year professional contract in October 2013.After performing well for both the under-18s and under-21s, he made his first team debut for the club as a substitute in their 2–0 loss against Leicester City at the John Smith's Stadium on 26 April 2014.