| Keltbray Consulting & Engineering Limited | Financial services | 2020 |
| Keltbray Electrification Plant Limited | Manufacturing | 2001 |
| Keltbray Group Limited | Financial services | 2015 |
| Keltbray Limited | Construction | 1976 |
| Keltbray Management Services Limited | Administrative & support | 2020 |
| Keltbray Nominees Limited | Professional & scientific | 2024 |
| Keltbray Plant Limited | Administrative & support | 1982 |
| Keltbray Reinforced Concrete Structures Limited | Financial services | 2020 |
| Kelterra Holdings Limited | Financial services | 2026 |
| Kempink Consulting Ltd | Administrative & support | 2023 |
| Kempton Park Estates Ltd | Real estate | 2019 |
| Kenstral Limited | Professional & scientific | 2012 |
| Kernow Advisory Limited | Information & communication | 2019 |
| Kerr Partnership LLP | | 2003 |
| Kestia Limited | Manufacturing | 2012 |
| Kestrel Property Investments Ltd | Real estate | 2007 |
| Keyes Advisory Ltd | Professional & scientific | 2022 |
| KFX Ltd | Arts & recreation | 2017 |
| Kgco Ltd. | Financial services | 2022 |
| Khelbill Property Investments Ltd | Real estate | 2016 |
| Khimasia & Robinson Limited | Financial services | 2016 |
| Kick Marketing and Communications Ltd | Professional & scientific | 2024 |
| Kinetic P M Limited | Professional & scientific | 2008 |
| Kings Water Coolers Limited | Other services | 2019 |
| Kingscote Pet Services Ltd | Other services | 2016 |
| Kingsland UK Holdco Ltd | Financial services | 2025 |
| Kingsmead Foley Road Residents Association (Claygate) Limited | Households | 1988 |
| Kingsway LIF Holdings Limited | Hospitality | 2009 |
| Kingswood Property Specialists Ltd | Administrative & support | 2011 |
| Kingsworthy Limited | Real estate | 2026 |
| Kitchen Junction Ltd | Hospitality | 2025 |
| KJR Group Ltd | Professional & scientific | 2020 |
| KL (Properties) Limited | Construction | 1974 |
| KML Occupational Health Limited | Health & social care | 2014 |
| KMR Aviation Services Ltd | Manufacturing | 2018 |
| Knights of Surrey Ltd | Transport & logistics | 2013 |
| Knightsbridge Treasury Ltd | Professional & scientific | 2022 |
| KNOWN2ME Limited | Information & communication | 2017 |
| Kodacc Limited | Professional & scientific | 2015 |
| Konclude AWS Limited | Water & waste | 2003 |
| Konclude Building Services Limited | Construction | 1996 |
| Konclude Capital Limited | Financial services | 2015 |
| Konclude Demolition Limited | Construction | 1981 |
| Konclude Environmental Ltd | Water & waste | 2008 |
| Konclude Environmental Materials Management Limited | Water & waste | 2009 |
| Konclude Group (Holdings) Limited | Construction | 1993 |
| Konclude Holdings Limited | Financial services | 2020 |
| Konclude Investments Limited | Other services | 2024 |
| Konclude Property and Investments Limited | Professional & scientific | 2018 |
| Konclude Structures Limited | Construction | 2016 |
| Konstructive Recruitment Services Limited | Administrative & support | 2004 |
| KS Capital Limited | Real estate | 2017 |
| Kshl Consultants Limited | Construction | 2018 |
| KSL Accounting Limited | Professional & scientific | 2021 |
| KSV United Limited | Real estate | 2022 |
| Kubicki Ltd | Professional & scientific | 2010 |
| Kulkarni Consulting Limited | Professional & scientific | 2014 |
| KW Equestrian Limited | Agriculture & fishing | 2017 |
| L & a Taylor Limited | Other services | 2013 |
| L a Kelly Design Ltd | Manufacturing | 2020 |
| L Bushell Ltd | Information & communication | 2015 |
| Lacuna Creates Ltd | Wholesale & retail | 2022 |
| Laidlaw & Company (UK) Ltd. | Financial services | 1999 |
| Laidlaw & Company International Limited | Financial services | 2007 |
| Laidlaw Holdings Limited | Financial services | 2007 |
| Lakeside Drive Residents Association Limited | Households | 1991 |
| Land Mine Productions Limited | Arts & recreation | 2022 |
| Land Software Ltd | Information & communication | 2020 |
| Landmark Design & Development Group Ltd | Construction | 2015 |
| Landmark Planned Maintenance Limited | Real estate | 2024 |
| Landmasters UK Developments Ltd | Real estate | 2023 |
| Lasercut by Ginge Ltd | Wholesale & retail | 2025 |
| Last Draft PIX Ltd | Information & communication | 2023 |
| Late Munchies Ltd | Hospitality | 2025 |
| Lavender Chef Limited | Hospitality | 2022 |
| LB Bell Property Limited | Real estate | 2025 |
| LB Design and Build Limited | Construction | 2022 |
| Lccs Accounting Services Ltd | Financial services | 2026 |
| Lccs Holdings Limited | Real estate | 2015 |
| Leadership Kintsugi Ltd | Professional & scientific | 2023 |
| Leaf & Stone Limited | Other services | 2014 |
| Lease United Kingdom Limited | Other services | 1995 |
| Legally Beautiful Limited | Extraterritorial | 2016 |
| Lenny Investments Limited | Real estate | 2021 |
| Leon Lettings 1 Ltd | Real estate | 2022 |
| Leoth Ltd | Other services | 2019 |
| Levelbay Limited | Financial services | 2000 |
| Levitate Aerial Imaging Ltd | Professional & scientific | 2017 |
| Lewis AW Ltd | Financial services | 2023 |
| Lexington Treasury Ltd | Professional & scientific | 2024 |
| Lezelle Mellet Financial Services Limited | Financial services | 2019 |
| Liam Rowley Ltd | Health & social care | 2010 |
| Libs Music Ltd | Wholesale & retail | 2025 |
| Licensed Trade International Ltd | Professional & scientific | 2012 |
| Licolo Ltd | Real estate | 2024 |
| Life Remixed Ltd | Education | 2018 |
| Lifford Developments Limited | Real estate | 2016 |
| Lightbulb Express Limited | Wholesale & retail | 2018 |
| Lighthouse Mediconsult Limited | Professional & scientific | 2021 |
| Lightwood Cardiff Ltd | Construction | 2020 |