| Site Solution AS | Wholesale & retail | 2024 |
| Skogbruksutstyr AS | Wholesale & retail | 2013 |
| Skogsentreprenør AS | Agriculture & fishing | 2025 |
| Skårdal Rådgiving AS | Professional & scientific | 2002 |
| Smørklepp Kraftverk AS | Energy | 2007 |
| Solring Anleggstenester AS | Professional & scientific | 2025 |
| Spegle AS | Real estate | 2022 |
| ST Bygg Og Rehabilitering AS | Construction | 2021 |
| Straumebui AS | Wholesale & retail | 2021 |
| Suigard Hyttegrend AS | Real estate | 2017 |
| Sømmen AS | Wholesale & retail | 2019 |
| T. Dyrdal Holding AS | | 2025 |
| Taxi Vinje AS | Transport & logistics | 2020 |
| Taxi Vinje Eigedom AS | Real estate | 2025 |
| Telemark Spælverring SA | Agriculture & fishing | 1974 |
| Telemark Tjenester Og Utleie AS | Administrative & support | 2025 |
| Telemark Trading AS | Wholesale & retail | 2021 |
| Telemark Utleiepartner AS | Manufacturing | 2021 |
| Tetris AS | Real estate | 2019 |
| Tilemork AS | Information & communication | 2024 |
| Tjønn AS | Real estate | 1965 |
| Trad Mat AS | Manufacturing | 2015 |
| Trollstigen Vannverk SA | Water & waste | 2019 |
| TT Industriservice AS | Real estate | 2019 |
| Tyrvelidvegen 84 AS | Real estate | 2020 |
| Tømrar Kollberg AS | Construction | 2026 |
| Uliveti Noreg AS | Wholesale & retail | 2018 |
| Vaagen Tomteselskap AS | Wholesale & retail | 1985 |
| Verkstadvegen 3 AS | Wholesale & retail | 2017 |
| Vesle Spire AS | Manufacturing | 2013 |
| Vest Telemark Eigendom AS | Real estate | 2021 |
| Vest-Telemark Rørleggerforretning AS | Construction | 1971 |
| Villmarksbygg AS | Construction | 2017 |
| Vinje Bilberging AS | Transport & logistics | 2008 |
| Vinje Bryggeri AS | Manufacturing | 2017 |
| Vinje Bukken AS | Wholesale & retail | 2023 |
| Vinje Datasenter Eigedom AS | Real estate | 2023 |
| Vinje Datasenter Holding AS | Real estate | 2021 |
| Vinje Golfsimulator AS | Public administration | 2025 |
| Vinje Invest AS | | 2016 |
| Vinje Kro AS | Hospitality | 2024 |
| Vinje Kro Eiendom AS | Real estate | 2025 |
| Vinje Mat Og Ferdaminne AS | Wholesale & retail | 2026 |
| Vinje Pub AS | Hospitality | 2025 |
| Vinje Rekneskapskontor AS | Professional & scientific | 2001 |
| Vinje Rør AS | Construction | 2015 |
| Vinje Rør Eigedom AS | Construction | 2010 |
| Vinje Sag Og Høvleri AS | Real estate | 2013 |
| Vinje Servicenter AS | Wholesale & retail | 1993 |
| Vinje Taxi AS | Transport & logistics | 2020 |
| Vinjekroa Eiendom AS | Hospitality | 2013 |
| Vinjesvingen Handel AS | Professional & scientific | 2005 |
| Vågslid Drift AS | Water & waste | 2023 |
| Xeva AS | Information & communication | 2016 |
| Å.K.B.Bygg AS | Construction | 2013 |
| Åmot Bilservice Eiendom AS | Real estate | 1993 |
| Øvre Vehus Renseanlegg SA | Water & waste | 2023 |
| Øyfjell AS | Wholesale & retail | 2015 |
| Øyfjell Kjøkken AS | Manufacturing | 2013 |
| Øyfjell Kontorbygg AS | Real estate | 2016 |
| Øyfjell Maskin AS | Construction | 1990 |
| Øyfjell Sag Og Høvleri AS | Manufacturing | 2014 |