Septemvri is known for its strong youth academy, which over the years has developed numerous players for Bulgaria's elite clubs and the national team.

At the end of the 1948–49 season, Septemvri is allowed to take part in a two-match play-off for entering first division against Marek Dupnitsa.

After both matches end with a 2:0 win for each team, a third game is played in which Septemvri falls 1:0 and remains in second division.

That same season, Septemvri finishes in 5th place and claims the Bulgarian Cup after a dramatic 4:3 win over Lokomotiv Sofia in extra time.

In March 2008, the club was heavily penalized after a scandalous match against FC Bansko, when coach Rumen Stoyanov ordered his players to leave the field, a serious offence according to Bulgarian Football Union regulations.

[2] With an executive decision, the BFU removed Septemvri from the V AFG and placed it in the A OFG, the Sofia Regional Football Group.

[3] Despite this setback, the club attained 1st place in the division in the 2008–09 season and qualified for a play-off match for entering the V AFG against FC Novi Iskar.

[8] The team finished their season in Second League in 2nd place, two points behind the winners of the group — Etar and qualified for the Promotion playoffs against elite member Montana.

[18] On 20 February 2018, Septemvri's executive director Georgi Markov died aged 46, three years after he suffered a heart attack.

[19] Septemvri secured their place in First League on 15 April 2018 after a 0–2 win over Dunav Ruse and qualified for European play-off quarter-finals.

[20] Back in the second tier after two seasons in the elite, Septemvri managed to maintain their good form and remained largely within the top three in the Second League, a strong candidate for promotion.

Septemvri only managed to make a cameo appearance in the elite, suffering immediate relegation back to the Second League for season 2023–24.

As of 10 February 2025 Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.