Sercombe came through the youth ranks at Exeter City, and signed a full professional contract with the club in June 2007. Sercombe made a number of appearances at reserve team level before making his debut on 11 August 2007 against Altrincham in the Conference National, coming on after just 11 minutes to replace the injured Andy Taylor. Sercombe began to play more regularly the following season and scored his first goal on 21 October 2008 as Exeter beat Portuguese Vale 3–1 at Vale Park.
On 20 March 2010, Sercombe scored in a 2–2 draw against Wycombe Wanderers.
On 9 April 2012, Sercombe scored twice as Exeter beat Leyton Orient 3–0 at Street James Park. The following game, he scored in a 3–2 defeat to relegation rivals Rochdale.
On 28 April, he scored for the fourth game in a row, however Exeter lost the game 4–1 to Carlisle United and were relegated from League One. Oxford United
On 13 May 2015, Sercombe signed a two year contract with Oxford United after his contract expired with former club Exeter City.