Notes
- On 12 June 2020 Chernomorets (Balchik), 14th in Vtora liga last season; withdraws. The club joins the Severoiztochna Treta liga.
- Suvorovo 1 (Suvorovo), 2nd last season; withdraws.
- Just before the start of the season newly promoted Svetkavitsa 2020 (Poroyno), 10th in OG Dorostol - iztok last season; merges with Dorostol Silistra (Silistra). This merger however is not registered legally in neither the Trade registry nor the MYS registry until the end of the season.
- On 4 August 2020, four days before the start of the season in Vtora liga and Elitna grupa (U-19), Dunav (Ruse) withdraws its teams from both competitions, after a change of ownership of the club is announced on the same day. On 5 August 2020 the men's team is entered into Severoiztochna Treta liga at the bye position of the schedule and its opening match is postponed. Since if a club withdraws voluntarily its men's team from a competition it has to be relegated two levels below, in order for its participation in Treta liga to be possible the club and the BFU agree that their Vtora liga license would be revoked, which allows Dunav to then participate in Treta liga. That decision however, as well as any official communication of the teams' withdrawals from Vtora liga and the Elitna grupa (U-19), is never announced officially by the BFU.
- On 13 August 2020 Benkovski (Byala) withdraws. The team enters OG Ruse.
- On 10 February 2021 Kubrat 2016 (Kubrat) withdraws. Its results still count and its opponents until the end of the season are awarded 3:0 wins.
- In April 2019 the Ministry of Youth and Sports creates a registry for all sports federations and their member clubs. Being registered within it is mandatory for any club that participates in a competition, organized by its sports federation. In football this requirement enters force with the start of the 2020/21 season and the first football clubs enters the registry in January 2020. At the start of the season in the group the following clubs are yet to be registered:
- Dorostol-Svetkavitsa (Silistra),
- Dunav (Ruse) - registered on 21 May 2021.
Notes
- Juventus 95 (Malchika), 14th last season; withdraws and enters into A OG Pleven.
- On 28 July 2020 Kom (Berkovitsa), 10th last season; withdraws and enters into A OG Montana
- On 3 August 2020 newly promoted Rasovo (Rasovo) merges with Plomie 2012 (Lom), fielding only youth teams last season; into Levski 2020 (Lom).
- Etar VT II (Veliko Tarnovo) plays its home games at the "Trifon Ivanov" st. in Veliko Tarnovo.
- In April 2019 the Ministry of Youth and Sports creates a registry for all sports federations and their member clubs. Being registered within it is mandatory for any club that participates in a competition, organized by its sports federation. In football this requirement enters force with the start of the 2020/21 season and the first football clubs enters the registry in January 2020. At the start of the season in the group the following clubs are yet to be registered:
- Levski 2020 (Lom) - registered on 20 August 2020.
Notes
- On 29 September 2020 Kyustendil (Kyustendil) is deducted 3 points due to its U17 team being removed from the league it competes in for walking off the field in a match.
- In April 2019 the Ministry of Youth and Sports creates a registry for all sports federations and their member clubs. Being registered within it is mandatory for any club that participates in a competition, organized by its sports federation. In football this requirement enters force with the start of the 2020/21 season and the first football clubs enters the registry in January 2020. At the start of the season in the group the following clubs are yet to be registered:
- Balkan 1929 (Botevgrad) - registered on 4 September 2020,
- Vihren (Sandanski) - registered on 11 August 2020,
- Marek 1915 (Dupnitsa) - registered on 11 August 2020,
- Nadezhda (Dobroslavtsi) - registered on 13 August 2020,
- Slivnishki geroy (Slivnitsa) - registered on 4 September 2020,
Notes
- Haskovo (Haskovo) plays its home games at the "Haskovo" st. in Haskovo.
- Vereya (Stara Zagora) plays its home games at the "Trace arena" st. in kv.Kolyo Ganchev, Stara Zagora.
- Dimitrovgrad 1947 (Dimitrovgrad) plays its home games at the "Minyor" st. in Dimitrovgrad.
- Maritsa 1921 (Plovdiv) plays its home games at the "Maritsa" st. in Plovdiv.
- Spartak 1947 (Plovdiv) plays its home games at the "Todor Diev" st. in Plovdiv.
- Chernomorets 1919 (Burgas) plays its home games at the "Chernomorets" st. in Burgas.
- The other teams play their home games at the home stadium of their club.
- In April 2019 the Ministry of Youth and Sports creates a registry for all sports federations and their member clubs. Being registered within it is mandatory for any club that participates in a competition, organized by its sports federation. In football this requirement enters force with the start of the 2020/21 season and the first football clubs enters the registry in January 2020. At the start of the season in the group the following clubs are yet to be registered:
- Izvor (Gorski izvor) - registered on 11 August 2020.