| Tkrj Holding AS | Education | 2009 |
| Tlah Holding AS | Transport & logistics | 2013 |
| TLH Invest AS | Real estate | 2004 |
| Tmhi AS | | 2025 |
| Tmind AS | | 2025 |
| To Tøffe Kokker Da | Other services | 2006 |
| Tobiassenbryggo Da | Real estate | 2009 |
| Tordenskjoldsg 48 AS | Real estate | 1996 |
| Total Trafikkhjelp AS | Transport & logistics | 2013 |
| Total Utleieservice AS | Administrative & support | 2019 |
| Toven Sijte SA | Real estate | 2026 |
| Trafikkskolen Mosjøen AS | Education | 2000 |
| Transportsentralen Mosjøen SA | Transport & logistics | 1965 |
| Tremto Da | Administrative & support | 2026 |
| Trond Tverå Holding AS | Construction | 2012 |
| Truck Og Maskin Agro AS | Wholesale & retail | 2018 |
| Truck Og Maskin AS | Other services | 2005 |
| Truck Og Maskin Utleie AS | Administrative & support | 2010 |
| Truck Og Maskin Ørbradden AS | Real estate | 1994 |
| TT Forsikring Og Finans Mosjøen AS | | 2018 |
| TT3 Holding AS | Construction | 2023 |
| Tundra Eiendom AS | Real estate | 2005 |
| Tundra Sol AS | Manufacturing | 2000 |
| Turmo Holding AS | Water & waste | 2008 |
| Tverå Bygg AS | Construction | 2023 |
| Tveråga Veglag SA | Real estate | 1957 |
| Tärna Vilt Event AS | Real estate | 2010 |
| Tømrerteam Helgeland AS | Construction | 2012 |
| Tøndels Fysikalske Institutt AS | Health & social care | 2014 |
| Ulvang Import Limited Nuf | Wholesale & retail | 2026 |
| Umami Kafe AS | Hospitality | 2026 |
| Umami Mosjøen AS | Hospitality | 2021 |
| Uni IT AS | Information & communication | 2017 |
| Urmaker Bjerve Mosjøen AS | Wholesale & retail | 2003 |
| Valaskjalf AS | Real estate | 2019 |
| Valter Svendsen AS | Construction | 2007 |
| Valåmo Bygg Og Eiendom AS | Construction | 2022 |
| Valåmo Eiendom AS | Administrative & support | 2021 |
| Valåmo Holding AS | | 2025 |
| Vam Industrial AS | Wholesale & retail | 2013 |
| Vatnan Transport AS | Transport & logistics | 2002 |
| Vato Eiendom AS | Real estate | 2019 |
| Ve Holding AS | Health & social care | 2022 |
| Vedlikeholdservice AS | Administrative & support | 2025 |
| Vefsn Asia Butikk AS | Wholesale & retail | 2022 |
| Vefsn Eiendom AS | Real estate | 2026 |
| Vefsn Eiendomsutvikling AS | Real estate | 2004 |
| Vefsn Fysikalske Institutt AS | Health & social care | 2001 |
| Vefsn Sveis AS | Manufacturing | 2018 |
| Vefsn Sveis Eiendom AS | Administrative & support | 2000 |
| Vefsn Sveis Holding AS | Hospitality | 2011 |
| Vefsn Trafikkskole AS | Education | 2012 |
| Vefsna Regnskap AS | Professional & scientific | 2004 |
| Vefsnavassdragets Fiskeforvaltning SA | Real estate | 2016 |
| Vefsnlaks AS | Arts & recreation | 1992 |
| Venezia Eiendom AS | Real estate | 2000 |
| Venezia Mosjøen AS | Hospitality | 2022 |
| Vepro AS | Manufacturing | 1990 |
| Verity AS | Professional & scientific | 2026 |
| Verity Group AS | Real estate | 2017 |
| Veset AS | Wholesale & retail | 2015 |
| Veset Eiendom AS | Mining & quarrying | 2012 |
| Vesterbekkmo Holding AS | Transport & logistics | 2010 |
| Vesterbekkmo Invest AS | | 2022 |
| Vesterbekkmo Transport AS | Transport & logistics | 2011 |
| Vex Frisør Mosjøen AS | Other services | 2020 |
| Vikgården AS | Hospitality | 2006 |
| Vip Barber AS | Other services | 2021 |
| Vipeveien Garasjelag SA | Real estate | 1982 |
| Vladas Byggservice AS | Construction | 2016 |
| Vogd Salg & Service Da | Wholesale & retail | 2013 |
| Vollanvegen 22 AS | Real estate | 2025 |
| Vollanveien 41 AS | Real estate | 2001 |
| Vår AS | Real estate | 2015 |
| Væxt Mosjøen AS | Professional & scientific | 2015 |
| W & W Eiendom AS | Real estate | 1988 |
| W.B Gym AS | Arts & recreation | 2023 |
| Wang AS | Wholesale & retail | 1990 |
| Wang Eiendom AS | Real estate | 1997 |
| Wask Holding AS | | 2025 |
| Westby Holding AS | Financial services | 2019 |
| Wiemna Holding AS | | 2026 |
| Wika Media AS | Information & communication | 2005 |
| Wos Holding AS | Real estate | 2015 |
| Wulff Eiendom AS | Arts & recreation | 1996 |
| Ynwa Eiendom AS | Real estate | 2013 |
| Ytterøra 23 AS | Real estate | 2021 |
| Ytterøra a AS | Real estate | 2019 |
| Ytterøra B AS | Real estate | 2019 |
| Ytterøra C AS | Real estate | 2021 |
| Yukon Invest AS | | 2023 |
| Zfokus AS | Information & communication | 2026 |
| Åmlidens El Aktiebolag | Construction | 1999 |
| Åsen Gård AS | Construction | 2024 |
| Åstveittunet AS | Real estate | 2019 |
| Øhman Bygg & Takst AS | Professional & scientific | 2023 |
| Øvsteng Anlegg Og Service AS | Construction | 2025 |
| Øya Biltekniske AS | Other services | 2008 |
| Øya Fyrverkeri AS | Wholesale & retail | 2013 |
| Øya Sør Eiendomsutvikling AS | Real estate | 2024 |