| Bakkstaul Invest AS | Financial services | 2016 |
| Birtedalen Kraftverk AS | Energy | 2022 |
| Bjåen AS | Professional & scientific | 2024 |
| Bjåen Holding AS | Professional & scientific | 2024 |
| Brødrene Klausen Da | Construction | 2010 |
| BTM Trafikkskule AS | Education | 2017 |
| Butikkdrift Høydalsmo AS | Wholesale & retail | 2017 |
| Bygg Og Anleggsservice AS | Agriculture & fishing | 2001 |
| Bygg Og Vedlikehald AS | Construction | 2019 |
| Carlos Maler AS | Construction | 2023 |
| Cervus Jaktreiser AS | Administrative & support | 2018 |
| Enhancher AS | Professional & scientific | 2019 |
| Esso Høydalsmo AS | Real estate | 2026 |
| Fredriksten AS | Professional & scientific | 2005 |
| Froland Sambeite SA | Agriculture & fishing | 1974 |
| Glomsdam Kraftverk AS | Energy | 2019 |
| Haddemyrvegen SA | Real estate | 1988 |
| Homme Gard Da | Agriculture & fishing | 2026 |
| Huldra Og Eg AS | Information & communication | 2010 |
| Høydalsmo Servicestasjon AS | Wholesale & retail | 2020 |
| Jordstøyl Eigedom AS | Real estate | 2000 |
| JSL Investering AS | Financial services | 2011 |
| Kleppo Eigedom AS | Real estate | 2015 |
| Kleppo Trevare AS | Manufacturing | 2004 |
| Kviteseid Byggevare AS | Administrative & support | 2013 |
| Kvålsgrend Pukk AS | Mining & quarrying | 2003 |
| Ladekraft AS | Energy | 2023 |
| Lofthus El-Tek AS | Professional & scientific | 2022 |
| Lofthus Liftjig AS | Professional & scientific | 2003 |
| Lofthus Utleige AS | Real estate | 2020 |
| Lårdal Tretopphytter AS | Hospitality | 2021 |
| M/M Holding AS | Professional & scientific | 2022 |
| Midtbøliane Veglag SA | Real estate | 1999 |
| Naurak Kraftverk AS | Energy | 2018 |
| RD Rekneskap AS | Professional & scientific | 2011 |
| SB Konsulent AS | Professional & scientific | 2017 |
| Skafså Kraftverk Ans | Energy | 1948 |
| Skatter - Kyrvestøyl Veglag SA | Real estate | 1986 |
| Småbruket Tvigyva AS | Hospitality | 2024 |
| Storstøga AS | Hospitality | 2024 |
| Ståland Holding AS | Agriculture & fishing | 2022 |
| Ståland Og Sønner AS | Construction | 2022 |
| Telefiber AS | Information & communication | 2006 |
| Telemark Hoppanlegg SA | Arts & recreation | 2002 |
| Telestrikk Eigedom Ans | Real estate | 1996 |
| Tnett AS | Energy | 2020 |
| Tore Aamot Invest AS | Financial services | 2015 |
| Vest Telemark Gravferdsbyrå AS | Other services | 2021 |
| Vest-Telemark Kraftlag AS | Energy | 1940 |
| Vest-Telemark Kraftlag Holding AS | Energy | 2020 |
| VTG Eigedom AS | Real estate | 2024 |
| Øyfjell Raudsinutan Løypelag Da | Arts & recreation | 2008 |