| Aarak Eiendom AS | Real estate | 2002 |
| Akademikerbonden AS | Real estate | 2006 |
| Alltidklar Hytteservice AS | Construction | 2008 |
| Amate Økonomi AS | Professional & scientific | 2025 |
| Audio Art AS | Wholesale & retail | 2000 |
| Best Treungen AS | Wholesale & retail | 2009 |
| Bjønntjønn Familiepark AS | Real estate | 2008 |
| BK Aarak AS | Construction | 2020 |
| Bygg Tre AS | Wholesale & retail | 1997 |
| Canvas Hotell AS | Hospitality | 2010 |
| Carl Erik Winther Larsen AS | Construction | 2012 |
| Cazo Eiendom AS | Real estate | 2021 |
| CL Service AS | Manufacturing | 2024 |
| Computer Systems AS | Information & communication | 2011 |
| Den Gamle Bru AS | Hospitality | 2025 |
| Eldbjørg Tveit Stykket | Agriculture & fishing | 2013 |
| Espestøylvegen Vegforening Ba | Other services | 2001 |
| Express Cargo AS | Transport & logistics | 2023 |
| Felehovet Utvikling AS | Construction | 2019 |
| Fjellstrand Senter AS | Real estate | 2008 |
| FMB Utvikling AS | Real estate | 2008 |
| Fredriksens Fabrikk AS | Manufacturing | 1992 |
| Fremtids Kollektivet Ans | Health & social care | 2000 |
| Fru Tveit AS | Wholesale & retail | 2014 |
| Gautefall Hytteutleie AS | Real estate | 2021 |
| Gautefallheia AS | Real estate | 2006 |
| Gautefallheia Hytteutleie AS | Administrative & support | 2017 |
| Gautefallheia Utvikling AS | Real estate | 2014 |
| GF Eiendom AS | Real estate | 2014 |
| Grova AS | Real estate | 2009 |
| Hagen Bygg Og Betong AS | Construction | 2022 |
| Hamoni AS | Health & social care | 2011 |
| Heimdal Høglandsfe Ans | Agriculture & fishing | 2000 |
| HS Utbygging AS | Real estate | 2021 |
| Husvassvegen Veglag SA | Real estate | 1945 |
| Iata Næring AS | Water & waste | 2007 |
| Instrutec AS | Wholesale & retail | 2006 |
| Jakob Tveit AS | Wholesale & retail | 1965 |
| Jettegrytene AS | Transport & logistics | 2025 |
| JGS Holding AS | Arts & recreation | 2006 |
| John Brommeland & Co Ans | Manufacturing | 1977 |
| Juvåna Fallrettighetslag SA | Energy | 2004 |
| Kjell Asbjørn Solberg AS | Water & waste | 1999 |
| Knut Haugsjå AS | Construction | 1999 |
| Kommuneguiden AS | Information & communication | 2026 |
| Kvarvåsen AS | Real estate | 2019 |
| LM Eigedom AS | Administrative & support | 2021 |
| Løvrak Anleggservice AS | Construction | 1998 |
| Mesterhytta Byggpartnere AS | Construction | 2022 |
| Mtpt AS | Professional & scientific | 2023 |
| NBH AS | Wholesale & retail | 2019 |
| Nissedal Booking AS | Hospitality | 2026 |
| Nissedal Hytteservice AS | Administrative & support | 2025 |
| Nissedal Næringsbygg AS | Real estate | 2020 |
| Nissedal Sandforedling AS | Mining & quarrying | 1992 |
| Nisser AS | Real estate | 2015 |
| Nisser Brygge AS | Real estate | 2005 |
| Nisser Bygg AS | Construction | 2013 |
| Nisser Eiendom AS | Real estate | 2019 |
| Nor-Mer AS | Professional & scientific | 1981 |
| Norwegian People AS | Manufacturing | 2014 |
| Notvad AS | Real estate | 2017 |
| Ormvasslivegen SA | Real estate | 2022 |
| Pointbreak AS | Professional & scientific | 2021 |
| RLN Support AS | Transport & logistics | 2016 |
| Rypelia AS | Real estate | 2012 |
| Skarvegen Veglag SA | Real estate | 2006 |
| Skogsbilveglaget Grytstøylvegen SA | Real estate | 1987 |
| Smarte Hytter AS | Real estate | 2009 |
| Solberg Eigedomsutvikling AS | Water & waste | 2008 |
| Solheia Hytteselskap AS | Real estate | 1997 |
| Sollid Multitjenester AS | Construction | 2024 |
| Sval AS | Manufacturing | 2023 |
| Sønderland Holding AS | Real estate | 2007 |
| Sørlands Bygg AS | Construction | 2019 |
| Takst & Bygningsvern AS | Real estate | 2020 |
| Telemark Drift AS | Professional & scientific | 2006 |
| Telemark Forlag AS | Information & communication | 2018 |
| Telemark Treindustri AS | Manufacturing | 2002 |
| Telemark Ullfilt AS | Manufacturing | 2024 |
| Treungen Bensin Og Service Ans | Wholesale & retail | 2008 |
| Treungen Eigedom AS | Real estate | 2025 |
| Treungen Event AS | Arts & recreation | 2019 |
| Treungen Hytta AS | Construction | 2017 |
| Treungen Næringsbygg AS | Real estate | 2016 |
| Treungen Rekneskap AS | Professional & scientific | 2022 |
| Treungen Sveis Og Service AS | Manufacturing | 2022 |
| Treungen Teknologipark AS | Real estate | 2013 |
| Treungen Utvikling AS | Real estate | 2019 |
| Treungen Varmepumpeservice AS | Other services | 2024 |
| Treungenfestival 2.0 AS | Arts & recreation | 2017 |
| Treungenfestival AS | Arts & recreation | 2008 |
| Trontveit Gard AS | Manufacturing | 2025 |
| Trosvikhytta SA | Real estate | 1996 |
| Utsjå Hyttegrend AS | Real estate | 2005 |
| Veterinær Moe AS | Professional & scientific | 2013 |
| Viltbutikken AS | Wholesale & retail | 2026 |
| Woodhouse Event AS | Arts & recreation | 2017 |
| WP Eiendomsutvikling AS | Real estate | 2014 |
| Ånundsbuoddane AS | Real estate | 2016 |