| Tannlege T Nordhagen AS | Health & social care | 2000 |
| Taxi Driver AS | Transport & logistics | 2021 |
| Tectgruppen AS | Professional & scientific | 2025 |
| Teem Door Consult AS | Professional & scientific | 2016 |
| Teke International AS | Wholesale & retail | 2022 |
| Teknobingo Årnes AS | Arts & recreation | 2008 |
| The Icelandic Hunting Club AS | Administrative & support | 2017 |
| Thomas Thoresen Tømmertransport AS | Construction | 2012 |
| Tica to AS | Professional & scientific | 1998 |
| Tinker Holding AS | | 2020 |
| TNG Holding AS | Financial services | 2005 |
| Tnsae AS | Wholesale & retail | 2023 |
| To Bakere AS | Manufacturing | 2015 |
| Tom Bråthen AS | Wholesale & retail | 2014 |
| Tomato International Food AS | Wholesale & retail | 2018 |
| Tomta II AS | Manufacturing | 1987 |
| Tomter Gård AS | Construction | 2024 |
| Tons Holding AS | Real estate | 2018 |
| Topp Demo AS | Professional & scientific | 2013 |
| Tor Amundsen Invest AS | Financial services | 2005 |
| Torbjørn Nilsen AS | Real estate | 2006 |
| Torkil Røseid AS | Real estate | 2020 |
| Torsonstua Sag SA | Manufacturing | 1983 |
| Tracktech Sverige AB Nuf | Construction | 2021 |
| TX Guardian AS | Professional & scientific | 2014 |
| Tømrermester Erik Hubred Nygård AS | Construction | 2021 |
| Tørn Invest AS | Real estate | 2008 |
| Udnes & Aas Bygg AS | Construction | 2017 |
| Udnes & Aas Utvikling AS | Real estate | 2012 |
| Udnes & Holter Entreprenør AS | Construction | 2020 |
| Udnes AS | Administrative & support | 2012 |
| Udnes Holding AS | Financial services | 2018 |
| Udnes Utemiljø AS | Administrative & support | 2005 |
| Udnes VVS AS | Construction | 2025 |
| Ullensaker Ved AS | Manufacturing | 2023 |
| Utsolgt AS | Wholesale & retail | 2021 |
| Ux & Tyting AS | Information & communication | 2025 |
| V&G Bygg Service AS | Construction | 2021 |
| Valia Eiendomsdrift AS | Real estate | 1989 |
| Vama AS | Administrative & support | 1994 |
| Vesttunvegen 10 AS | Real estate | 2025 |
| Vignita AS | Information & communication | 2017 |
| Viken Kroppsterapi AS | Other services | 2026 |
| Viken Lyd Og Lys AS | Arts & recreation | 2020 |
| Viken-Service AS | Transport & logistics | 2026 |
| VK System AS | Construction | 2024 |
| Vorma Økonomi Og Regnskap SA | Professional & scientific | 1993 |
| Walstad Maskinservice AS | Manufacturing | 2013 |
| Watz Holding AS | Health & social care | 2021 |
| Webfrakt AS | | 2016 |
| Weng AS | Administrative & support | 2007 |
| Wennemo Holding AS | | 2006 |
| Wetronix AS | Manufacturing | 2023 |
| Winther Studio Nuf | Wholesale & retail | 2024 |
| Woiwoi Klær Og Interiør AS | Wholesale & retail | 2016 |
| Wok Ben Tre Vu AS | Hospitality | 2021 |
| Ynshagen Invest AS | | 2021 |
| Zigma Eiendom AS | Real estate | 2008 |
| Årnes Auto AS | Wholesale & retail | 2023 |
| Årnes Bil & Karosseri AS | Other services | 1987 |
| Årnes Bilberging AS | Transport & logistics | 1988 |
| Årnes Blomster AS | Wholesale & retail | 1983 |
| Årnes Dental AS | Manufacturing | 1989 |
| Årnes Eiendom AS | Real estate | 1997 |
| Årnes Eiendom Holding AS | Real estate | 2015 |
| Årnes Elektriske AS | Wholesale & retail | 2002 |
| Årnes Elektro AS | Construction | 2007 |
| Årnes Hagaskog AS | Administrative & support | 1927 |
| Årnes Handel & Utleie AS | Administrative & support | 2015 |
| Årnes Helsebygg AS | Health & social care | 2013 |
| Årnes Hårstasjon AS | Other services | 2020 |
| Årnes Legesenter AS | Health & social care | 2019 |
| Årnes Legetjenester AS | Health & social care | 2026 |
| Årnes Næringssenter AS | Real estate | 2017 |
| Årnes Pizzadrift AS | Hospitality | 2020 |
| Årnes Revisjon AS | Professional & scientific | 1988 |
| Årnes Småbedriftssenter AS | Real estate | 2020 |
| Årnes Sport AS | Wholesale & retail | 1982 |
| Årnes Tannregulering & Tannhelse AS | Health & social care | 2020 |
| Årnes Treningsstudio AS | Arts & recreation | 2026 |
| Årnes Vannverk SA | Water & waste | 1909 |
| Årnes Vel Eiendom AS | Real estate | 1978 |
| Årnes Veterinærklinikk AS | Professional & scientific | 2008 |
| Årnes Zoo AS | Wholesale & retail | 2008 |
| Østgården Drift AS | Administrative & support | 2014 |
| Østspar AS | Real estate | 1996 |