- American Embassy Sofia
- Bulgarian Customs Agency
- Bulgarian National Bank
- BULGARGAZ
- Delegation of the European Commission to Bulgaria
- Deutsche Telekom
- EDIBUL
- Ernst & Young
- Inter Data Systems
- HIMCO-Vratza (Chemical works)
- Humbold University
- Kozloduy Nuclear Power Plant
- Ministry of Defence
- Ministry of Energy and Energy Resources
- Ministry of Environment and Waters, PMU
- Ministry of Finances
- Ministry of Regional Development and Construction
- Ministry of Transport, Information Technology and Communications
- National Electrical Company
- National Institute of Statistics
- NOKIA Bulgaria
- Patent Office of the Republic of Bulgaria
- PLAMA-Pleven (Oil extraction works)
- Risk Engineering
- S & SK Co, Korea
- SM Consulta
- Sofia Airport
- TBI Bank
- TBI Credit/Leasing/Rent
- Telcom Engineering
- Trade Point Sofia
- Transact Europe
- Union Fenosa, Spain
- T-Systems International
- Telecommunication research center at the University of Limerick, Ireland
- UniCredit Consumer Financing
- University of Magdeburg
- University of Plovdiv
- US Customs Service
