Public transport services in Sofia are realized by:

3 in-house transport operators (100% municipally-owned):

• “Stolichen Elektrotransport” EAD, operating tram and trolleybus transport.
• “Stolichen Autotransport” EAD, operating bus transport.
• “Metropoliten” EAD, operating the metro.

3 private transport operators, operating bus transport.

• Union Ivkoni OOD
• KRAT-S AD
• Eridantrans OOD

The provision of public transport services by in-house and private transport operators is arranged on the basis of public service contracts (PSC) with Sofia Municipality.