Born in Chelmsford, Halford began his career with Colchester United where he came through the youth system before moving to Reading in 2007. His stay at Reading was a short one and Halford transferred to Sunderland later the same year. After failing to hold down a regular place with Sunderland, he moved to Wolverhampton Wanderers in 2009 and later to Portsmouth in 2010, Nottingham Forest in 2012, and Rotherham United in 2015. Halford has also played for Charlton Athletic, Sheffield United, Brighton & Hove Albion and Birmingham City on loan at various points in his career, as well as representing England at under-20 level.