| Thune Invest AS | | 2026 |
| Thuve Marketing AS | Professional & scientific | 2022 |
| Tideturn AS | | 2025 |
| Tigerworks AS | Information & communication | 2022 |
| Tiki Investment AS | Professional & scientific | 2016 |
| Time for Beauty Studio AS | Other services | 2025 |
| Timeflex Systemer AS | Information & communication | 2007 |
| Tinka Eiendom AS | Real estate | 2017 |
| Tinnies AS | Wholesale & retail | 1997 |
| Tinvest AS | Financial services | 1985 |
| Tison Holding AS | Professional & scientific | 2018 |
| Titanum AS | | 2024 |
| Tittins På Torvet AS | Other services | 2013 |
| Tixit AS | Financial services | 2007 |
| Tjorven Garn Avd. Sandefjord AS | Wholesale & retail | 2021 |
| Tjøllingveien 991 AS | Real estate | 2019 |
| TK Digital AS | Information & communication | 2023 |
| TK Import AS | Wholesale & retail | 2020 |
| TK Innovation AS | Information & communication | 2023 |
| Tk&H Holding AS | Information & communication | 2021 |
| Tkbo AS | | 2015 |
| TKS Bygg AS | Construction | 1994 |
| TKT AS | Construction | 2020 |
| TLS Eiendom AS | Real estate | 2004 |
| Tmbryhn Engineering AS | Professional & scientific | 2020 |
| TMD Holding AS | | 2026 |
| Tmi Invest AS | Professional & scientific | 2018 |
| TN Bygg Og Eiendom | Real estate | 2024 |
| TNB Sandefjord AS | Wholesale & retail | 2000 |
| TNL Ør AS | Health & social care | 2025 |
| TNS Invest AS | Manufacturing | 2005 |
| Toast Invest AS | | 2022 |
| Toft Bygg AS | Construction | 2026 |
| Tokadilatika AS | Professional & scientific | 2026 |
| Tokat AS | Real estate | 2020 |
| Tom Fisher AS | Real estate | 2010 |
| Tom Og Tom - Service Ans | Administrative & support | 2000 |
| Tomasz AS | Construction | 2022 |
| Tombre Bim Consult AS | Professional & scientific | 2025 |
| Tombre Bygg AS | Construction | 2021 |
| Tombre Consult AS | Professional & scientific | 2021 |
| Tommy Haukås AS | Professional & scientific | 2012 |
| Toms Hageglede AS | Administrative & support | 2013 |
| Tomta Mat AS | Wholesale & retail | 2019 |
| Tomva AS | Manufacturing | 2015 |
| Tone Westrum AS | Other services | 2014 |
| Tonga Produksjoner AS | Arts & recreation | 2020 |
| Top Nordic Uv Tech AS | Professional & scientific | 2021 |
| Top Water Flow AS | Water & waste | 1995 |
| Topconsult AS | Professional & scientific | 1984 |
| Topp Trafikkskole AS | Education | 2019 |
| Toppen Frisører AS | Other services | 2020 |
| Toppen-Invest AS | | 2021 |
| Tor Mikkelsen AS | Wholesale & retail | 1965 |
| Torden Bygg AS | Administrative & support | 2024 |
| Torell Pump AS | Wholesale & retail | 2024 |
| Torg AS | Real estate | 2018 |
| Torger Holding AS | Wholesale & retail | 2012 |
| Torgers Eiendom AS | Wholesale & retail | 2012 |
| Torgers Skraphandel Og Gjenvinning AS | Wholesale & retail | 2012 |
| Torget 1 Eiendom AS | Real estate | 2016 |
| Torggata 14 AS | Real estate | 2007 |
| Torggata 15 AS | Real estate | 2021 |
| Torggata P.K Eiendom AS | Real estate | 2019 |
| Torggaten 18 Sandefjord AS | Real estate | 2007 |
| Torggaten 9 AS | Real estate | 1994 |
| Torinor Holding AS | Real estate | 1988 |
| Torinor Sport AS | Wholesale & retail | 1982 |
| Torp Bygg Og Eiendom AS | Real estate | 2019 |
| Torp Campus AS | Real estate | 2017 |
| Torp Consulting AS | Administrative & support | 2006 |
| Torp Elektro AS | Construction | 2002 |
| Torp Flytanking AS | Transport & logistics | 2016 |
| Torp Holding AS | Wholesale & retail | 2019 |
| Torp Hotel AS | Hospitality | 1990 |
| Torp IT AS | Real estate | 2000 |
| Torp Konferansesenter AS | Real estate | 2015 |
| Torp Næringsutvikling AS | Real estate | 1999 |
| Torp Parkering 1 AS | Transport & logistics | 2009 |
| Torp Services AS | Administrative & support | 2006 |
| Torp Økonomi AS | Professional & scientific | 2007 |
| Torpveien 125 AS | Real estate | 2005 |
| Torsdag AS | Real estate | 2018 |
| Torsdag Holding AS | Real estate | 2018 |
| Torsdag JR. AS | | 2022 |
| Torton Capital Management AS | Hospitality | 2014 |
| Torvet 1A AS | Real estate | 2012 |
| Torvet 1A Kontor AS | Real estate | 2020 |
| Torvet Eiendom Sandefjord AS | Real estate | 1998 |
| Tosy AS | Professional & scientific | 2008 |
| Total Klima AS | Construction | 2015 |
| Totmo Da | Wholesale & retail | 1999 |
| Tove E. Røed AS | Financial services | 2005 |
| Tovoll Holding AS | | 2023 |
| TPL Invest AS | Real estate | 2016 |
| Tpo Holding AS | | 2022 |
| Tracking Systems AS | Professional & scientific | 2002 |
| Transport & Renhold AS | Transport & logistics | 2018 |
| Transport Invest AS | Transport & logistics | 2007 |
| Transportsentralen Vestfold AS | Transport & logistics | 1987 |