In season 1962/63, Barnet finished 2nd in the Athenian League, seven points behind champions Enfield. There was talk of extending the Isthmian League with four teams to be invited from the Athenian League. As one of the top Athenian League clubs, Barnet must have anticipated that they would be among the clubs to receive an invite, but it was not to be. Champions, Enfield, Sutton United, HitchinTown and Hendon got the call and Barnet were left in a depleted and less competitive Athenian League.
The following season, 1963/64, the Athenian League was reduced from 16 clubs to 14 with the four clubs who had left being replaced by just Dagenham and Maidenhead United. A second division of 14 clubs was added, with the top division being the Premier Division and the lower one, Division One.
Rumours started that Barnet might be invited to join the Isthmian League at the end of the season. Barnet won the Athenian League, as they were expected to do given the drop in quality that season, finishing 4 points ahead of neighbours, Finchley. However, again no invitation from the Athenian League was forthcoming and it was Wealdstone that were to join the Isthmian League. The Athenian League announced that both divisions were to be extended to 16 clubs with Leatherhead, Worthing and EdgwareTown being promoted from Division One.
Barnet were again expected to win the Premier Division title and the 1964/65 season was a successful one with Barnet winning the title by 11 points from Leyton while in the FA Cup, Barnet reached the 3rd round for the first time, only going down 3-2 at Underhill to 2nd division, Football league club, Preston North End after an epic performance.
However, frustrated by being ignored by the Isthmian League and with the decline in quality of the Athenian League due to so many top clubs departing, the club desperately needed a new challenge and, in April 1965, the club applied for membership to the Southern League Division One.
The Southern League was a professional league and would mean an end to Barnet’s amateur status and would mean that they would no longer be able to play in the FA Amateur Cup, which was a prestigious tournament with the final played at Wembley. At this point, the FA Trophy was till a few years in the future and the only real tournament replacing the FA Amateur Cup would be the Southern League Cup, not really a trophy of the same calibre, to say the least.
Many people also displayed concern about the club being able to fund players wages and the much higher travel costs of the Southern League which was spread over a much wider, geographical area. The club hoped that they could retain most of the current players, though there was also a worry that many would not want to turn professional, which would debar them from playing for the national amateur teams. Promotion to the Southern Premier League as soon as possible was seen as vital to avoid disenchantment setting it and to encourage high attendances.
Generally, arguments for and against were about equal. There was also, at the same time, a proposal, from Andrew Letts, for a new professional league if enough southern Amateur clubs would be interested.
In May, Barnet’s application proved successful and they, along with DunstableTown, were elected to the Southern League Division One. Barnet had burned their boats now and their amateur days were now behind them and the club began life as a professional club.