In 2002–03 Canvey Island finished as Premier Division runners-up for a third consecutive season, but the following year saw them win the division to earn promotion to the Conference National. The season had also seen them reach the FA Cup first round for a third time; again drawn to face Southend, they lost 3–2 in a replay at Park Lane after a 1–1 draw at Roots Hall and the FA Trophy final, where they lost 3–2 to Hednesford Town. Another first round appearance in 2004–05 ended in a 4–0 defeat to Aldershot Town. After two seasons at the fifth level, King decided the poor attendances did not justify continued investment in the club and they took voluntary demotion to Division One North of the Isthmian League. In 2007–08 they finished fifth in the division, qualifying for the promotion play-offs. After defeating AFC Sudbury 3–2 in the semi-finals, they beat Redbridge 5–4 on penalties in the final after the match had ended 1–1 and were promoted back to the Premier Division.