When the Greater London League merged with the Spartan League at the end of the 1970–71 season, Deal's first team opted not to join the merged league and instead took over from their reserve team in the new Kent League. They won the League Cup in 1981–82, beating Erith & Belvedere in the final. They were league runners-up in 1988–89 and again in 1998–99, also winning the League Cup in the latter season with a win over VCD Athletic. The 1999–2000 season saw them win the league, reach the final of the FA Vase and beat Chippenham Town 1–0 in the Wembley final, as well as winning the Kent Senior Trophy. The club's success that season also saw them reach the final of the Kent League Cup, but they could not play the final due to fixture congestion. The Kent League was renamed the Southern Counties East League in 2013, and when the league gained a second division in 2016, they became members of the Premier Division.