| Troms Elektro AS | Tromsø | 2015 |
| Troms Invest AS | Brøstadbotn | 2007 |
| Troms Maritime Automation AS | Tromsø | 2024 |
| Troms Maskin Team AS | Bardu | 2001 |
| Troms Portservice AS | Tromsø | 2003 |
| Troms Rør AS | Oldervik | 2016 |
| Troms Takservice AS | Finnsnes | 1996 |
| Tromsbygg Entreprenør AS | Storsteinnes | 2014 |
| Tromsdalen Bygg AS | Tomasjord | 2019 |
| Tromsdalen Elektro AS | Tromsdalen | 2010 |
| Tromsø Bergsprenging AS | Tromsø | 2018 |
| Tromsø Betong Team AS | Tromsø | 2018 |
| Tromsø Bygg & Tre Ans | Tromsø | 2025 |
| Tromsø Bygg Og Renovering AS | Tromsdalen | 2021 |
| Tromsø Bygg Service AS | Kvaløysletta | 1989 |
| Tromsø Crew AS | Krokelvdalen | 2019 |
| Tromsø Elektro AS | Tromsø | 1996 |
| Tromsø Entreprenør AS | Liland | 2004 |
| Tromsø Flis Og Varme AS | Kvaløya | 2020 |
| Tromsø Gulv AS | Tromsø | 2022 |
| Tromsø Håndverkerlag AS | Tromsdalen | 2015 |
| Tromsø Håndverksservice AS | Tromsø | 2008 |
| Tromsø Maskin Og Utemiljø AS | Tromsø | 2014 |
| Tromsø Maskin Team AS | Tromsø | 2021 |
| Tromsø Parkett- Og Golvservice Ans | Tromsø | 1987 |
| Tromsø Rørleggerforretning AS | Tromsø | 1997 |
| Tromsø Rørservice AS | Tromsø | 2022 |
| Tromsø Takmontering AS | Tromsdalen | 1989 |
| Tromsø Varmepumpeservice AS | Tromsø | 2023 |
| Tromsø Ventilasjon AS | Moen | 2013 |
| Tromsø VVS AS | Tromsø | 2025 |
| Tron Gevelt Consulting AS | Mjøndalen | 2022 |
| Tron Gevelt Holding AS | Mjøndalen | 2005 |
| Trond Abrahamsen VVS AS | Oslo | 2016 |
| Trond Arve Kommedal AS | Sandnes | 2016 |
| Trond Aune Maskinstasjon AS | Åfjord | 2005 |
| Trond E Bruaset Holding AS | Ler | 2017 |
| Trond Halvorsen Invest AS | Stavanger | 2005 |
| Trond Hedland AS | Sandnes | 1989 |
| Trond Heggland AS | Bergen | 2000 |
| Trond Hjelset AS | Molde | 2013 |
| Trond K Larsen AS | Lillesand | 2020 |
| Trond Larsen AS | Færvik | 2014 |
| Trond Lind AS | Krokelvdalen | 1995 |
| Trond M Brekstad Holding AS | Brekstad | 2022 |
| Trond M. Sognnes AS | Leirvik I Sogn | 2006 |
| Trond Nilsson Holding AS | Ottestad | 2018 |
| Trond Nordmark AS | Harstad | 1998 |
| Trond Nødland Malerforretning AS | Frekhaug | 2025 |
| Trond Olsen Mur & Flis AS | Drøbak | 2014 |
| Trond Rædergård Holding AS | Brekstad | 2016 |
| Trond Sveberg Bygg AS | Holmestrand | 1991 |
| Trond Tverå Holding AS | Mosjøen | 2012 |
| Trondenes Maskin AS | Harstad | 2020 |
| Trondheim Bad Og Byggteknikk AS | Klæbu | 2021 |
| Trondheim Betong AS | Trondheim | 2006 |
| Trondheim Betongsaging AS | Ranheim | 2020 |
| Trondheim Bygg AS | Trondheim | 2026 |
| Trondheim Bygg Og Bad AS | Heimdal | 2018 |
| Trondheim Bygg-Service AS | Trondheim | 2007 |
| Trondheim Byggteknikk AS | Trondheim | 2021 |
| Trondheim Eiendomsservice AS | Trondheim | 2015 |
| Trondheim El & Montasje AS | Lundamo | 2008 |
| Trondheim El AS | Flatåsen | 2015 |
| Trondheim Elektro AS | Tiller | 2021 |
| Trondheim Elektroservice AS | Trondheim | 2008 |
| Trondheim Glass-Service AS | Trondheim | 1988 |
| Trondheim Kobber & Blikkslager AS | Heimdal | 1989 |
| Trondheim Malerservice AS | Trondheim | 2009 |
| Trondheim Malerteam AS | Skatval | 2013 |
| Trondheim Mur Og Våtrom II AS | Heimdal | 2023 |
| Trondheim Murservice AS | Trondheim | 2004 |
| Trondheim Port Og Gjerdeservice AS | Lundamo | 2012 |
| Trondheim Reeferservice Ans | Trondheim | 2002 |
| Trondheim Rørservice AS | Trondheim | 2023 |
| Trondheim Rørvakt AS | Klæbu | 2019 |
| Trondheim Tak AS | Tiller | 2005 |
| Trondheim Tak Og Fasade AS | Trondheim | 1994 |
| Trondheim Ventilasjon AS | Trondheim | 2021 |
| Trondheim VVS AS | Flatåsen | 2025 |
| Trondhjem Bolig AS | Trondheim | 2021 |
| Tronds Bygg AS | Råde | 2016 |
| Tronds Mur Og Flis AS | Hønefoss | 2014 |
| Trone Bolig AS | Bryne | 2021 |
| Trones Maskin AS | Stamsund | 2017 |
| Trones Maskin Drift AS | Stamsund | 2020 |
| Trones Tak & Fasade AS | Loddefjord | 2025 |
| Tronfjell Maskin AS | Alvdal | 2014 |
| Tronn Thoresen AS | Kvinesdal | 2014 |
| Tronrud Betong AS | Sande I Vestfold | 2019 |
| Tronsaune VVS AS | Trondheim | 2001 |
| Tronsholen Utvikling AS | Stavanger | 2012 |
| Tronstadhagen Maskin AS | Leksvik | 2008 |
| Trosaf AS | Tromsø | 2025 |
| Trosvik Elektro AS | Brevik | 2026 |
| Trosvik Malerservice AS | Fredrikstad | 2015 |
| Trotech AS | Tana | 2021 |
| Trovåg Anlegg Og Transport AS | Fosser | 2021 |
| Troy Capital AS | Oslo | 2022 |
| Troya AS | Sandnes | 2005 |