| TMH Holding AS | | 2025 |
| TN Invest AS | Professional & scientific | 2013 |
| To Dahl Holding AS | Financial services | 2017 |
| To Polymer AS | Financial services | 2005 |
| To to AS | Real estate | 2005 |
| Tobakk Spesialisten AS | Wholesale & retail | 2025 |
| Tobias Gadeberg AS | Professional & scientific | 2024 |
| Toddler Mobility AS | Professional & scientific | 2023 |
| Tomt Og Eiendom AS | Real estate | 2015 |
| Tonbe AS | Transport & logistics | 2020 |
| Top Real Eiendom AS | Real estate | 2023 |
| Topp Drift AS | Administrative & support | 2023 |
| Tops Market Jessheim AS | Wholesale & retail | 2026 |
| Tore Kværner AS | Real estate | 2002 |
| Torggata 2 Sarpsborg AS | Real estate | 2018 |
| Tosand Holding AS | | 2025 |
| Totalprosjekt AS | Construction | 1997 |
| Trafikalt Kompetansesenter AS | Education | 2023 |
| Transport Cargo AS | Transport & logistics | 2022 |
| Transport Tawiah Saanti AS | Transport & logistics | 2025 |
| Tre & Profil AS | Wholesale & retail | 2007 |
| Tre Holding AS | Hospitality | 2022 |
| Trendpartner AS | Wholesale & retail | 2006 |
| Trinn Prosjektledelse AS | Professional & scientific | 2019 |
| Triva Drift AS | Administrative & support | 2023 |
| Trolldrift AS | Hospitality | 2013 |
| Tron Johan Wiig AS | Information & communication | 2008 |
| Trond Fladby AS | Real estate | 2005 |
| Trondheimsvegen 55 AS | Real estate | 2015 |
| Trondheimsvegen 953 AS | Real estate | 2022 |
| Trondheimsveien 251 AS | Real estate | 2007 |
| Trondheimsveien 98 AS | Real estate | 2016 |
| Trondsen Eiendom AS | Real estate | 2024 |
| Trons Transport AS | Transport & logistics | 2018 |
| Trygg Renhold AS | Administrative & support | 2017 |
| Trækompagniet AS | Wholesale & retail | 2006 |
| TTD Transport Tjenester Doan AS | Transport & logistics | 2025 |
| Tufs Holding AS | | 2025 |
| Tufsingdalen Eiendom AS | Real estate | 2016 |
| Tunet Pub Drift AS | Arts & recreation | 2023 |
| Tunhøvd AS | Professional & scientific | 2025 |
| Tut & Kjør Trafikkskole AS | Education | 2011 |
| Tveitan Prosjekt AS | Professional & scientific | 2025 |
| Two Monkeys AS | Hospitality | 2021 |
| Two P Consulting AS | Professional & scientific | 2023 |
| Tyritomt Holding AS | Real estate | 2016 |
| Tyrox AS | Real estate | 2014 |
| Tærud Eiendom AS | Real estate | 2015 |
| Tærud Eiendom Jessheim AS | Real estate | 2018 |
| Tærudgården Råholt AS | Real estate | 2015 |
| Tøk Invest AS | Real estate | 2017 |
| Uavhengig Kontroll Ullensaker AS | Professional & scientific | 2013 |
| Udh Nordbymoen AS | Real estate | 2024 |
| Udh Vilberg AS | Real estate | 2009 |
| Uki Drift AS | Real estate | 2010 |
| Uki Eiendom AS | Real estate | 2010 |
| Ulf Robert Øverbye AS | | 2023 |
| Ulf Øverbye A/S | Wholesale & retail | 1967 |
| Ulfur AS | Construction | 2025 |
| Ullensaker 123 AS | Wholesale & retail | 2025 |
| Ullensaker Auto AS | Other services | 2021 |
| Ullensaker Dampsag Og Høvleri Holding AS | Real estate | 2005 |
| Ullensaker Eiendom AS | Construction | 1994 |
| Ullensaker Ferdigplen AS | Agriculture & fishing | 2013 |
| Ullensaker Fysioterapi AS | Health & social care | 2014 |
| Ullensaker Holdning AS | Construction | 2023 |
| Ullensaker Legesenter AS | Health & social care | 2023 |
| Ullensaker Tannlegesenter AS | Health & social care | 2018 |
| Ullensaker Transport AS | Transport & logistics | 2017 |
| Ullensaker Utleie AS | Administrative & support | 2014 |
| Ullensaker Ventilasjon & Kjøleservice AS | Construction | 2024 |
| Uller Eiendom AS | Real estate | 2001 |
| Ullr GNP FKN2 AS | Real estate | 2026 |
| Ullr GNP N3 AS | Real estate | 2026 |
| Ullr GNP NK2A AS | Real estate | 2026 |
| Ullr Nordkisa AS | Real estate | 2026 |
| Ullr Utvikling AS | | 2025 |
| Ulnes Consult AS | Professional & scientific | 2023 |
| Ulvene Tømrerservice AS | Construction | 2021 |
| Umbra Holding AS | | 2021 |
| Unik Solutions AS | Construction | 2023 |
| Urban Gipsy AS | Wholesale & retail | 2020 |
| Utleiemegleren Jessheim AS | Real estate | 2020 |
| V Bygger Og Investerer AS | Construction | 2014 |
| V. Holm AS | Construction | 2019 |
| Vakt Og Kontrolltjenester AS | Administrative & support | 2021 |
| Vaktgruppen Romerike AS | Administrative & support | 2017 |
| Valhallavegen 10 AS | Real estate | 2016 |
| Vallhallavegen Eiendomsutvikling AS | Real estate | 2019 |
| Vamø AS | Professional & scientific | 2020 |
| Vanes Holding AS | Wholesale & retail | 2018 |
| Vangenfjellet AS | Real estate | 2019 |
| Vanica AS | Wholesale & retail | 2021 |
| Vanilla AS | | 2022 |
| Vantamars AS | Transport & logistics | 2025 |
| Vardul AS | Information & communication | 2026 |
| Vavylon AS | Administrative & support | 2024 |
| Vedking AS | Professional & scientific | 2026 |
| Vedlikehold Service & Eiendom AS | Real estate | 1996 |
| Veiberggata 15 AS | Real estate | 2026 |