In January 2008, the contracts of Killock and fellow Town youngster Simon Eastwood were extended until 2009.[5] On 15 February, he joined Conference North side Hyde United on loan. He made his debut the next day in Hyde's 2–1 defeat to AFC Telford United.[6] He was highly praised for his performances at the Tigers[citation needed] and received the man of the match award for his performance in Hyde's 3–1 win over Worcester City a week later.[7] He returned to the Galpharm Stadium at the end of the season.
Killock spent September 2008 on loan at Conference North side Harrogate Town. He made his debut on 2 September in their 2–0 win over A.F.C. Telford United, and returned to Huddersfield on 7 October.
In January 2009, new manager Lee Clark sent Killock out on a month's loan to Oxford United. He made his debut in the FA Trophy loss to York City, before making his league debut in a 1–0 win over Altrincham. At the end of the loan spell, Killock was released from his Huddersfield contract and signed a permanent deal with Oxford United until the end of the season.[8] Killock's contract was then extended, despite his progress having been disrupted by injuries,[9] then, at the start of the 2009–10 season, he joined Conference North side A.F.C. Telford United on loan.[10] The move was made permanent in November 2009.[11]
Killock was named AFC Telford United captain in August 2010, and that season captained the Bucks to promotion via the play-offs to the Conference National, he also won a player of the season award at the clubs awards night. He was released by the club in May 2012.[12] After his release from Telford he then signed for former club Harrogate.
He signed for Northern Premier League Premier League side Stalybridge Celtic on a free transfer in September 2021[14] and departed from the club in June 2022. In July 2022, he signed with Mossley.[15] He departed on November 15, 2023.[16] The following day, Killock joined Ossett United.[17] Ahead of the 2024-25 season, Killock moved to Golcar United.[18]
In July 2025, Killock retired from football. [19]
