| Kings BIN Cleaning Ltd | Administrative & support | 2024 |
| Kings Court (Berkhamsted) Management Company Limited | Households | 1984 |
| Kings GAS and Electrical Limited | Construction | 2015 |
| Kings Langley RTM Company Ltd | Households | 2011 |
| Kings-Barber Leighton Ltd | Other services | 2023 |
| Kingshill Grange (High Wycombe) Management Company Limited | Households | 2010 |
| Kingsway Land and Developments Ltd | Construction | 2017 |
| Kingswell Designs Ltd | Wholesale & retail | 2022 |
| Kingswood Driveways & Patios Ltd | Administrative & support | 2018 |
| Kingswood Estate Management Limited | Households | 2000 |
| Kingswood Nursery Ltd | Real estate | 2019 |
| Kingswood Recruitment Ltd | Administrative & support | 2024 |
| Kinslowe Creative Limited | Professional & scientific | 2026 |
| Kirkhill ULC Unlimited | Professional & scientific | 2024 |
| Kirkwood Properties Limited | Real estate | 2018 |
| Kissing Gate Wildlife Limited | Agriculture & fishing | 2026 |
| KIT ME UP Limited | Professional & scientific | 2012 |
| Kite Construction Management Limited | Construction | 2022 |
| Kitsbury Court Management (NO.2) Company Limited | Households | 1994 |
| Kitty's Rawr Store Ltd | Wholesale & retail | 2025 |
| Kizo Consulting Ltd | Information & communication | 2024 |
| KJB Creative Limited | Professional & scientific | 2023 |
| KK9 Ltd | Other services | 2022 |
| KKD Commerce Ltd | Wholesale & retail | 2024 |
| Klassu Ltd | Construction | 2020 |
| KLH Partners Ltd | Professional & scientific | 2025 |
| Klingaer Limited | Professional & scientific | 2021 |
| Klub Padel Ltd | Arts & recreation | 2026 |
| KMG Estates (Immingham) Limited | Real estate | 2022 |
| KNG Contracting Ltd | Construction | 2025 |
| Knowledge 4 Strength Ltd | Information & communication | 2024 |
| Knowles Property Rental Limited | Real estate | 2021 |
| Knowlhill Management Limited | Real estate | 2004 |
| Kobdale Limited | Wholesale & retail | 2013 |
| Kockum Sonics (UK) Limited | Manufacturing | 1989 |
| Koda Consulting Ltd | Administrative & support | 2015 |
| Kokoe Film Limited | Information & communication | 2016 |
| Kolbus UK Limited | Manufacturing | 1969 |
| Kombimatec Machines Ltd | Manufacturing | 1984 |
| Komorebi Consultant Limited | Professional & scientific | 2023 |
| Koncikas Ltd | Professional & scientific | 2024 |
| Kontrole Limited | Information & communication | 2025 |
| Kosta Splosh Ltd | Other services | 2018 |
| Koto Property Management Ltd | Real estate | 2025 |
| Kotta Property Ltd | Real estate | 2024 |
| KR Engineering Services Limited | Manufacturing | 2016 |
| Krause & Hall Holdings Limited | Construction | 2025 |
| Krause & Hall Limited | Construction | 2007 |
| KRB Consulting Ltd | Administrative & support | 2019 |
| Kristal Vision Ltd | Information & communication | 2015 |
| KRP (UK) Limited | Arts & recreation | 2009 |
| KS2 Commercial Limited | Wholesale & retail | 2018 |
| KS3 Storage Limited | Real estate | 2018 |
| KSL Fabrication Ltd | Construction | 2024 |
| KT Aesthetics Ltd | Other services | 2026 |
| Kumar Consultancy Limited | Information & communication | 2006 |
| Kurbside Kitchen and Bar Limited | Hospitality | 2014 |
| Kured Search Ltd | Administrative & support | 2022 |
| KV Hair Studio Ltd | Other services | 2025 |
| KW Consulting Solutions Limited | Professional & scientific | 2016 |
| Kymera Media Limited | Information & communication | 2016 |
| Kyrkrons Investment Limited | Real estate | 2018 |
| Kytona Limited | Information & communication | 2025 |
| Kyza Bathrooms Limited | Construction | 2025 |
| L & B Auctions Limited | Wholesale & retail | 2023 |
| L & R Electrical Contractors Ltd | Construction | 2025 |
| L Holden Consulting Limited | Professional & scientific | 2026 |
| L T Car Sales Ltd | Wholesale & retail | 2020 |
| L&B Market Ltd | Wholesale & retail | 2024 |
| L. Pelling Services Limited | Information & communication | 2016 |
| L.Bainbridge Enterprises Limited | Real estate | 2025 |
| LA Ecommerce Limited | Wholesale & retail | 2020 |
| Laan Van Meerdervoort Limited | Information & communication | 1995 |
| Labelrail (UK) Company Limited | Wholesale & retail | 2023 |
| Laboratory Arts Limited | Health & social care | 2018 |
| Laloaia Engineering Ltd | Construction | 2026 |
| Lami Hand Car Wash Ltd | Administrative & support | 2020 |
| Land Potential Ltd | Real estate | 2024 |
| Landscape Services Direct Limited | Other services | 1996 |
| Lang-Ag Ltd. | Administrative & support | 2014 |
| Langham Mews Management Company Limited | Households | 2005 |
| Lansdowne Place Taplow (Management) Limited | Households | 2016 |
| Lanslide Limited | Professional & scientific | 2015 |
| Lantern Facilities Ltd | Administrative & support | 2026 |
| Lara Rickard Ltd | Wholesale & retail | 2016 |
| Larch Communications Ltd | Professional & scientific | 2020 |
| Larr Residential Property Limited | Real estate | 2023 |
| Lasao Ltd | Hospitality | 2024 |
| Lateral Design Studio Limited | Manufacturing | 2011 |
| Lateral Platform Solutions Ltd | Information & communication | 2025 |
| Latimer Resources Limited | Professional & scientific | 1997 |
| Latte DAH Limited | Hospitality | 2015 |
| Laura Collinge Consulting Ltd | Professional & scientific | 2025 |
| Lavinia Arena Limited | Administrative & support | 2016 |
| Lawes Electrical Ltd | Construction | 2024 |
| Lawson Scientific Limited | Professional & scientific | 2018 |
| Layosa Limited | Health & social care | 2015 |
| LB Haulage Ltd | Transport & logistics | 2025 |
| LB Himalaya Ltd | Hospitality | 2016 |
| LB Taverns Ltd | Hospitality | 2026 |