| Hansen Salg Og Montering AS | Wholesale & retail | 2016 |
| Happy & Strong AS | Wholesale & retail | 2018 |
| Hartz Eiendomsselskap AS | | 2022 |
| Hartz K G Holding AS | Professional & scientific | 2019 |
| Hartz Ressurs AS | Professional & scientific | 2020 |
| Hauk Sport AS | Wholesale & retail | 1998 |
| Havdal AS | | 2022 |
| Herreavdelingen AS | Wholesale & retail | 2000 |
| Hiltech Holding AS | | 2023 |
| Holm Investments AS | | 2024 |
| Holm Skogsdrift AS | Agriculture & fishing | 2004 |
| House of Ibsen AS | Wholesale & retail | 2026 |
| Hovland Invest Bernadagolf AS | Real estate | 1998 |
| HRK Anlegg AS | Construction | 2023 |
| HTH Prosjekt AS | Professional & scientific | 2017 |
| HWK Eiendom AS | Real estate | 2019 |
| HWK Invest AS | Construction | 2010 |
| Idehus Modum AS | Construction | 2011 |
| Idrettens Hall AS | Real estate | 2025 |
| Industriveien 38J AS | Real estate | 2014 |
| Industriveien 40 AS | Real estate | 2005 |
| Intraoral AS | Wholesale & retail | 2021 |
| IP Norway AS | Administrative & support | 2008 |
| Isafold Byggtjenester AS | Construction | 2026 |
| Isolve AS | Professional & scientific | 1997 |
| Jahr Bilservice AS | Other services | 2012 |
| Jahr Maskin AS | Construction | 2018 |
| Jens Jacobsen Trading AS | Manufacturing | 2022 |
| Jensen Mek AS | Manufacturing | 1995 |
| Ji Skinstad Invest AS | Financial services | 2005 |
| Jonvi Eiendom AS | Real estate | 2023 |
| K H Skorta Holding AS | | 2023 |
| K-Bo Holding AS | Financial services | 2017 |
| K.Pandur AS | Real estate | 2015 |
| K.R. Holding AS | Financial services | 2012 |
| Kafe Kvisten AS | Hospitality | 2019 |
| Kaggefoss Embretsfoss Elveeierlag SA | Real estate | 1992 |
| Karolines Holding AS | | 2025 |
| Katfoss Eiendom AS | Real estate | 2006 |
| Ke Frisør AS | Other services | 2018 |
| Kevin MX AS | Arts & recreation | 2018 |
| Kim Bråthen AS | | 2022 |
| Kjøll Øivind Og Trond Ans | Agriculture & fishing | 1995 |
| KLC Eiendom AS | Real estate | 2021 |
| Klimaservice Modum AS | Construction | 2012 |
| Kohi Byggpartner AS | Construction | 2024 |
| Koios AS | Information & communication | 2014 |
| Kolberg Eiendom AS | Real estate | 1979 |
| Kollerud Holding AS | Other services | 2017 |
| Kongshaug Invest AS | Financial services | 2011 |
| Kongsrud Mekaniske AS | Manufacturing | 2023 |
| Kopland AS | Arts & recreation | 2020 |
| Krokvik Eiendom AS | Real estate | 2016 |
| Krøderveien Eiendom AS | Real estate | 2026 |
| Kvantadent AS | Wholesale & retail | 2026 |
| Kørt AS | | 2020 |
| Lampeveien 7 AS | Real estate | 2015 |
| Landbrukstjenester Buskerud SA | Agriculture & fishing | 1997 |
| Lappebakken AS | Construction | 2017 |
| Leba Invest AS | | 2023 |
| Led Ringen AS | Wholesale & retail | 2018 |
| Leren AS | Professional & scientific | 2014 |
| Letmolie Bygg AS | Construction | 2024 |
| Letmolie Holding AS | Construction | 2024 |
| LF Teknikk AS | Construction | 2020 |
| Lilleåsgata 4 AS | Real estate | 2022 |
| Linderud Og Thingelstad Skog Da | Agriculture & fishing | 2022 |
| Lun Property AS | Real estate | 2020 |
| Luxushair AS | Wholesale & retail | 2015 |
| Lybeck Og Engens Maleservice Ans | Construction | 1993 |
| Løbi Invest AS | | 2026 |
| Macb Invest AS | Real estate | 2015 |
| Malermester Frank Hansen AS | Construction | 2023 |
| Malmveien V. Spone - Sysle SA | Real estate | 1971 |
| Maria Fuhre Holding AS | Financial services | 2012 |
| Mbergan Holding AS | Real estate | 2021 |
| Midtfylket Entreprenør AS | Construction | 2018 |
| Midtsem Holding AS | | 2026 |
| Midtun Drift AS | Professional & scientific | 2020 |
| Midtun Invest AS | Professional & scientific | 2019 |
| Milan Restaurant AS | Hospitality | 2023 |
| Mirkani AS | Hospitality | 2026 |
| Modulvegger Produksjon AS | Manufacturing | 1990 |
| Modum Auto Senter AS | Wholesale & retail | 1997 |
| Modum Bilservice AS | Other services | 2021 |
| Modum Boligtjenester AS | Construction | 2026 |
| Modum Containerutleie AS | Administrative & support | 2023 |
| Modum Drift Holding AS | | 2026 |
| Modum Graving Og Transport AS | Construction | 2023 |
| Modum Holding AS | Construction | 2018 |
| Modum Isolering AS | Construction | 2019 |
| Modum Kabel-Tv AS | Information & communication | 1996 |
| Modum Sag Og Brøyting AS | Administrative & support | 2026 |
| Modum Skilt & Dekor Da | Professional & scientific | 2000 |
| Modum Trafikkskole AS | Education | 2006 |
| Modumstua AS | Hospitality | 2009 |
| Mortentjernveien SA | Real estate | 1961 |
| Murergruppen AS | Construction | 2022 |
| My Golf AS | Arts & recreation | 2023 |
| My Profil AS | Wholesale & retail | 2010 |