| Kansas Management Limited | Households | 1985 |
| Kantabile Limited | Real estate | 2012 |
| Kardeshler Ltd | Wholesale & retail | 2023 |
| Karma Suitsya Limited | Wholesale & retail | 2019 |
| Katie and ALF Limited | Extraterritorial | 2012 |
| Katie Pope Ltd | Wholesale & retail | 2025 |
| KAY TEE Transport Limited | Other services | 2012 |
| Kaymac Engineering Ltd | Professional & scientific | 2026 |
| Kaysara Limited | Arts & recreation | 1984 |
| KBS Property Development Limited | Construction | 2011 |
| KCC Digital Ltd | Professional & scientific | 2024 |
| Keay Fire Safety Ltd | Professional & scientific | 2023 |
| Keels Development Ltd | Other services | 2023 |
| Keen on Training Limited | Information & communication | 2019 |
| Keith Miller Insurance Services Limited | Financial services | 1990 |
| Kellond Group Limited | Real estate | 2025 |
| Kenward Plant Limited | Administrative & support | 2012 |
| Kestrel Court (Epsom) Limited | Households | 2022 |
| Kevin Bridgman Consulting Limited | Professional & scientific | 2012 |
| Keystone Brickwork Group Ltd | Construction | 2020 |
| Keystone Designs Limited | Professional & scientific | 2015 |
| Keystone Securities Limited | Administrative & support | 2012 |
| KI Dynamics Ltd | Information & communication | 1995 |
| KI' Plumbing & Heating Ltd | Construction | 2014 |
| Kids Critters Limited | Health & social care | 2021 |
| Kieser Media Ltd | Professional & scientific | 2022 |
| Kilburn Girl Limited | Arts & recreation | 2021 |
| Kilovale Limited | Construction | 1990 |
| Kimzu Management Ltd | Professional & scientific | 2023 |
| Kincroy Investments Limited | Real estate | 2024 |
| Kineagle Investments Limited | Real estate | 2023 |
| Kinfield Investments Limited | Real estate | 2022 |
| Kingfisher Close (Warren Road) Management Company Limited | Real estate | 2021 |
| Kingshold Beauty Ltd | Other services | 2026 |
| Kinhampton Limited | Real estate | 2024 |
| Kinver Capital Limited | Real estate | 2021 |
| Kinwater Investments Limited | Real estate | 2023 |
| Kirkstall Flat Management (Dorking) Limited | Real estate | 1974 |
| Klidos Limited | Wholesale & retail | 1963 |
| KLM Regent Limited | Construction | 2004 |
| KLO Media Enterprises Ltd | Professional & scientific | 2025 |
| Knight Bros. Contract Flooring Limited | Construction | 2013 |
| Knights Court Residents Association Limited | Households | 1988 |
| Knights Drycleaners London Limited | Other services | 2023 |
| Kodata Ltd | Information & communication | 2020 |
| Kombeo Limited | Information & communication | 2019 |
| Kong Industries Ltd | Manufacturing | 2024 |
| Kraken Doors Ltd | Construction | 2024 |
| Ksaa Limited | Hospitality | 2025 |
| Kskg Property Limited | Real estate | 2019 |
| KSX Studio Ltd | Professional & scientific | 2024 |
| Kuan YIN Ltd | Financial services | 2026 |
| Kumar Care Services Ltd | Health & social care | 2022 |
| KURDY1 Limited | Wholesale & retail | 2025 |
| Kynexus Ltd | Professional & scientific | 2026 |
| Kyralily Limited | Real estate | 2016 |
| L & M Salons Limited | Other services | 2020 |
| L L Studios Ltd | Professional & scientific | 2020 |
| L T Property Services Limited | Real estate | 2009 |
| L&E Cleaning Ltd | Other services | 2021 |
| L&H Capital Ltd | Financial services | 2011 |
| L&H Finance Ltd | Financial services | 2002 |
| L'Ecurie UK Limited | Hospitality | 2014 |
| L. P. D. Consulting Limited | Professional & scientific | 2005 |
| L.H. Cleaning Services Limited | Administrative & support | 2008 |
| LA Aesthetics Group Ltd | Other services | 2024 |
| LA Aesthetics Solutions Ltd | Other services | 2021 |
| Ladies That DO Limited | Other services | 1987 |
| Lady Petrol Ltd | Wholesale & retail | 2020 |
| Ladymount Residents Company Limited | Households | 1994 |
| Lakedale Contract Office Furniture Ltd | Administrative & support | 1998 |
| Lakeside House Limited | Administrative & support | 2012 |
| LAM Consulting Ltd | Administrative & support | 2018 |
| Lamanzi Limited | Financial services | 2007 |
| Lambert Close Management Company Limited | Households | 2024 |
| Lancaster House Trading & Consulting Ltd | Administrative & support | 2011 |
| Land and Waste Solutions Limited | Professional & scientific | 2011 |
| Land Logic Limited | Real estate | 2001 |
| Landens Farm Management Company Limited | Professional & scientific | 2016 |
| Landman Tree Surgery and Forestry Limited | Agriculture & fishing | 2014 |
| Landscapewell Ltd | Administrative & support | 2024 |
| Langdale Dunn Property Group Ltd | Extraterritorial | 2023 |
| Langham House RTM Company Limited | Households | 2020 |
| Lantean Limited | Information & communication | 2016 |
| Lara Clark Floristry Ltd | Wholesale & retail | 2024 |
| Larchwood Place Number Two Residents Company Limited | Households | 2002 |
| Larchwood Place Residents Company Limited | Households | 2001 |
| Largo Training Associates Limited | Professional & scientific | 2022 |
| Lark Arden Ltd | Wholesale & retail | 2019 |
| Laser Roofing Limited | Construction | 2012 |
| Lashthetics Limited | Other services | 2023 |
| Latchmere Properties Limited | Construction | 1972 |
| Latchmere Securities Limited | Construction | 1993 |
| Late Birthday Project Limited | Arts & recreation | 2025 |
| Lateral Thought Engineering Limited | Professional & scientific | 2013 |
| Lateralus Life Sciences Ltd | Professional & scientific | 2024 |
| Lavington Freehold Management Limited | Households | 2020 |
| Lawnbots Limited | Other services | 2025 |
| Lazy Studios Limited | Information & communication | 2019 |
| LBE Building Limited | Construction | 2023 |