Billy came through all the age groups in the Chelsea Academy and won the FA Youth Cup in 2010. He signed a new four-year contract in September 2011 before going on to feature regularly for the reserves throughout the ensuing campaign.

Billy scored his first goal of the 2012/13 campaign in a 3-1 defeat away at Fulham in October, and was ever-present for the Chelsea Under-21 side prior to a move to League One Colchester on a month’s loan on 11 January 2013. The move was then extended until the end of the season in February, when after five appearances Billy had helped stem a run of nine straight defeats as Colchester battled against relegation into League Two.

The midfielder is well known to Yeovil fans after he scored his first professional goal against the Glovers whilst on loan at Colchester United.