| Torsnes Eiendomsselskap AS | Real estate | 2019 |
| Torvbyen Drift AS | Real estate | 1999 |
| Torvbyen Gull Og Ur AS | Wholesale & retail | 2026 |
| Torvstikkeren 1B AS | Real estate | 2024 |
| Tosano AS | Professional & scientific | 2019 |
| Total Holding AS | Wholesale & retail | 2025 |
| Total Packaging AS | Wholesale & retail | 2001 |
| Total Security Da | Administrative & support | 2002 |
| Touch-Up Da | Wholesale & retail | 2008 |
| Tptt AS | Wholesale & retail | 2021 |
| TPX Holding AS | | 2007 |
| TR Byggtjenester AS | Construction | 2019 |
| Tradingpartner AS | Wholesale & retail | 2008 |
| Trafikkdrift AS | Administrative & support | 2019 |
| Transel Arkitekter AS | Professional & scientific | 2025 |
| Transpire AS | Information & communication | 2024 |
| Traraveien 7 AS | Real estate | 2005 |
| Treade AS | Wholesale & retail | 1987 |
| Trevia AS | Administrative & support | 1990 |
| Trippel Tre AS | Professional & scientific | 2005 |
| Trippeveien 2 AS | Real estate | 2020 |
| Trippeveien Eiendom AS | Real estate | 2014 |
| Tristeinene AS | Professional & scientific | 2017 |
| Triumph Eq AS | Agriculture & fishing | 2018 |
| Trivium AS | Professional & scientific | 2021 |
| Trivium Holding AS | | 2025 |
| Troll Gruppen AS | | 2026 |
| Troll Natural Energy AS | Wholesale & retail | 2012 |
| Trond Horg Ellingsen AS | Wholesale & retail | 1976 |
| Trosvik Malerservice AS | Construction | 2015 |
| Trosvikstranda 48 AS | Real estate | 2026 |
| Trosvikstranda Næring Grunnplan AS | Real estate | 2021 |
| Trosvikstranda Næring Kontor AS | Real estate | 2021 |
| Trosvikstranda Parkering AS | Real estate | 2021 |
| Trosvikstranda Utvikling AS | Real estate | 2020 |
| Trosvikstranda Vest Eiendom AS | Real estate | 2018 |
| Trosvikstranda Øst Eiendom AS | Real estate | 2018 |
| Troy-Øien Invest AS | | 2023 |
| Truls Aarum AS | Professional & scientific | 1992 |
| Truls Meland AS | | 2000 |
| Trump AS | Professional & scientific | 2024 |
| Trycons AS | Professional & scientific | 2023 |
| Trygg Frakt Østfold AS | Information & communication | 2025 |
| Trygg Kapital AS | Professional & scientific | 2015 |
| Tryvann-Oslo Studentfestival AS | Administrative & support | 2025 |
| TS Handel AS | Wholesale & retail | 2022 |
| Tumar AS | Hospitality | 1994 |
| TV Bussen AS | Administrative & support | 2018 |
| Tvehold AS | | 2026 |
| Tømrerteam Viken AS | Construction | 2023 |
| Ulv Ulv AS | Information & communication | 2015 |
| Ums Fredrikstad AS | Wholesale & retail | 2017 |
| Umsf AS | Wholesale & retail | 2020 |
| Underhaugsgata 1 AS | Real estate | 2019 |
| Unik Design Da | Other services | 2001 |
| Unique Hudpleie AS | Other services | 2013 |
| Unite Global AS | Information & communication | 2014 |
| Universal Tannhelse AS | Health & social care | 2022 |
| Upside Holding AS | Real estate | 2014 |
| Ut Av Boksen Media AS | Professional & scientific | 2025 |
| Uteplassen.No AS | Wholesale & retail | 2013 |
| V-L Invest AS | Real estate | 2015 |
| Vabenken 14 AS | Real estate | 2012 |
| Vaj Holding AS | | 2024 |
| Valadia AS | Information & communication | 2023 |
| Valentis Norway AS | Professional & scientific | 2013 |
| Valhalla Holding AS | Real estate | 2013 |
| Valhallsgate AS | Real estate | 2016 |
| Valve Rør AS | Construction | 2025 |
| Van Der Weele AS | Health & social care | 2010 |
| Varebil AS | Wholesale & retail | 2018 |
| Vauco AS | | 2025 |
| Veem Kapital AS | Real estate | 2021 |
| Vegetar AS | Real estate | 2013 |
| Veine Karterud AS | Professional & scientific | 2025 |
| Vela-Eiendom AS | Real estate | 2020 |
| Veldigodt AS | Wholesale & retail | 2026 |
| Veldigodt Holding AS | | 2026 |
| Velværestua AS | Other services | 2021 |
| Vennebygg & Eiendom AS | Real estate | 2020 |
| Vesterelven Terrasse AS | Real estate | 1997 |
| Vestsiden Bygg & Interiør AS | Real estate | 2016 |
| Vetten AS | Financial services | 2009 |
| Veum Dugnad AS | | 2026 |
| Veum Hageby AS | Real estate | 2014 |
| Veum Hageby Tunet AS | Real estate | 2021 |
| VEUM PLANTESENTER ANS Larsen, Hansen & Erlandsen. | Wholesale & retail | 1989 |
| Veumtek AS | Construction | 2025 |
| Veumveien 15 AS | Real estate | 2000 |
| Viamatic Elektro AS | Construction | 2022 |
| Vibework AS | Information & communication | 2026 |
| Vicom Torp AS | Professional & scientific | 2013 |
| Vidd Studio AS | Information & communication | 2026 |
| Vig Eiendom AS | Real estate | 2022 |
| Vig Eiendomsdrift AS | Real estate | 2022 |
| Vigger Eiendom AS | Real estate | 2020 |
| Viken Import & Utleie AS | Administrative & support | 2021 |
| Viken Nevropsykologi AS | Health & social care | 2021 |
| Viken Portservice AS | Construction | 1997 |
| Viken Produksjoner AS | Information & communication | 2019 |