| JT Elektro Support Da | Construction | 2015 |
| Julie Og Amalie Da | Wholesale & retail | 2024 |
| Julstex AS | | 2024 |
| JW Consulting AS | Professional & scientific | 2023 |
| JW Holding AS | | 2015 |
| Jørgen Aa Holding AS | | 2019 |
| Jørn Skogen AS | Professional & scientific | 2022 |
| K.M.S Eiendom AS | Real estate | 2005 |
| K.M.S. Holding AS | Real estate | 2019 |
| K1 Invest AS | Real estate | 2023 |
| Kabo Konsult AS | Professional & scientific | 2017 |
| Kafe Søstrene AS | Hospitality | 2023 |
| Kafe À Hjørnet AS | Hospitality | 2023 |
| Kaffebox AS | Wholesale & retail | 2015 |
| Kaffeforretningen AS | Hospitality | 2014 |
| Kalnes Holding AS | Real estate | 2018 |
| Kalnes Syd 1 AS | Real estate | 2023 |
| Kalnes Syd 2 AS | Real estate | 2023 |
| Kalnes Syd 3 AS | Real estate | 2023 |
| Kalnes Utleie AS | Real estate | 2018 |
| Kalnesveien 1 AS | Real estate | 2017 |
| Kamacabi AS | Wholesale & retail | 2021 |
| Kao Thai Takeaway AS | Hospitality | 2024 |
| Kardigan AS | Information & communication | 2012 |
| Karl J Paulsen Eiendom AS | Real estate | 2002 |
| Karl J. Paulsen AS | Real estate | 2005 |
| Karl J. Paulsen Bakeri Og Konditori AS | Manufacturing | 2013 |
| Karl J. Paulsen Eiendom III AS | Real estate | 2025 |
| Karl Johans Legesenter Da | Health & social care | 2023 |
| Karl Johansgate 10 AS | Real estate | 2023 |
| Karoline Marberg AS | | 2024 |
| Kastanjen Blomster Da | Wholesale & retail | 2002 |
| Kato AS | Wholesale & retail | 2012 |
| Katz AS | Real estate | 2018 |
| Kebab House Sarpsborg AS | Hospitality | 2014 |
| Kebab Pizza House 1 AS | Hospitality | 2018 |
| Kef Holding AS | Real estate | 2009 |
| Keramikk-Kollektivet Ans | Manufacturing | 2024 |
| Ketil Koppang Holding AS | Real estate | 2013 |
| Kim Hue Holding AS | Hospitality | 2016 |
| Kingsrød Eiendomsselskap AS | Real estate | 2002 |
| Kirkegata 27 AS | Real estate | 2021 |
| Kirkegaten Bensin & Service AS | Wholesale & retail | 1971 |
| Kirkeveien 5 Eiendom AS | Real estate | 2015 |
| Kjerringåsen Alpinsenter AS | Arts & recreation | 1988 |
| Kjølberg Bygg AS | Construction | 2022 |
| KK Design Røyem Og Bjørnrud Ans | Manufacturing | 1993 |
| Klargjøring Av Båt Nuf | Manufacturing | 2021 |
| Klavestad-Entreprenør AS | Construction | 2012 |
| Klinikk A.B. AS | Health & social care | 2019 |
| Klisjé Digital AS | Manufacturing | 2005 |
| Klokkergården 3 AS | Real estate | 1991 |
| Klokkergården 5 AS | Real estate | 2006 |
| Klokkergårdveien 16 AS | Real estate | 2004 |
| Klokkergårdveien 28 AS | Real estate | 2017 |
| Klokkergårdveien Bilservice AS | Other services | 2014 |
| Knapstad Næring AS | Real estate | 2010 |
| Knapstad Næring II AS | Real estate | 2015 |
| Knapstad Vestre AS | Real estate | 2005 |
| Knapstadhagen Næring AS | Real estate | 2024 |
| Knausen Invest AS | Wholesale & retail | 2002 |
| Knut Pinaas Anleggsservice AS | Construction | 2021 |
| Konglelund AS | Real estate | 2014 |
| Kopiservice Da | Wholesale & retail | 1987 |
| Korell Invest AS | Administrative & support | 2014 |
| Kornel's Malerservice AS | Construction | 2020 |
| Kortreist Naturstein AS | Wholesale & retail | 2022 |
| Kortsentralen AS | Wholesale & retail | 2026 |
| Kos Invest AS | Real estate | 2006 |
| Koseklumpen AS | Wholesale & retail | 2022 |
| Kotas AS | Real estate | 2005 |
| Kreatriks Design Ans | Professional & scientific | 2014 |
| Krogseth AS | Construction | 1991 |
| Krydderhylla Finsnekring Ans | Manufacturing | 1995 |
| Kullsyre AS | | 2022 |
| Kultakeskus OY | Wholesale & retail | 1995 |
| Kultorp Eiendom AS | Real estate | 2019 |
| Kulås Barnehage AS | Education | 2022 |
| Kurland Eiendom AS | Real estate | 2004 |
| Kurlandveien 2 Eiendom AS | Real estate | 2012 |
| Kvaenveien 3 AS | Real estate | 2023 |
| Kvartal 64 AS | Real estate | 2021 |
| Kvartal 98 AS | Real estate | 2007 |
| Kvass Norge AS | Information & communication | 2019 |
| Kvass Tech AS | Information & communication | 2025 |
| Kwa Holding AS | Real estate | 2016 |
| Kyrre Berg AS | Wholesale & retail | 2001 |
| L Evensen Eftf AS | Wholesale & retail | 1977 |
| L. Johansen Consult AS | Professional & scientific | 2013 |
| L. Johansen Eiendom AS | Real estate | 2014 |
| L. Johansen Invest AS | Professional & scientific | 2013 |
| L.Andersen Holding AS | | 2023 |
| L.O.S Invest AS | | 2025 |
| Lainell AS | Information & communication | 2021 |
| Lajo Holding AS | | 2024 |
| Lande Auto AS | Other services | 1983 |
| Lande Bygg AS | Construction | 2020 |
| Lande Frisør AS | Other services | 1999 |
| Lande Fysioterapi Eiendom AS | Real estate | 2015 |
| Lande Gård Barnehage AS | Education | 2018 |