| Kington Adventures Limited | Administrative & support | 2026 |
| Kinisy Group Ltd | Financial services | 2025 |
| Kinisy Ltd | Manufacturing | 2023 |
| Kinna Homes Limited | Construction | 2004 |
| Kinnrod Logistics Ltd | Transport & logistics | 2020 |
| Kins Barber Limited | Other services | 2022 |
| Kirby Property & Trading Ltd | Real estate | 2025 |
| Kirkstyle Holdings Limited | Financial services | 2020 |
| Kiss IT Support and Logistics Limited | Information & communication | 2016 |
| KIT Revolution Ltd | Other services | 2018 |
| Kitchen Ventilation Projects Limited | Construction | 2019 |
| Kite Holidays Ltd | Administrative & support | 2024 |
| Kite Runners Capital Inc Ltd | Financial services | 2022 |
| Kite Runners Care Ltd | Health & social care | 2025 |
| Kivernells Limited | Other services | 1964 |
| Kiwi Accounting Limited | Professional & scientific | 2019 |
| KJ Compliance Limited | Professional & scientific | 2025 |
| KJP Plumbing Ltd | Construction | 2008 |
| Kjpillay Limited | Real estate | 2022 |
| Klane Limited | Professional & scientific | 2025 |
| Klone London Limited | Wholesale & retail | 2023 |
| KMA Designs Limited | Professional & scientific | 2026 |
| KMW Plumbing Heating and Renewables Limited | Construction | 2026 |
| Knibbs Dental Surgery Limited | Health & social care | 2007 |
| Knibbs Tdmp Holding Limited | Financial services | 2022 |
| Knight Fire & Security Ltd | Construction | 2006 |
| Knight Goodhead Limited | Professional & scientific | 2008 |
| Knightwood Accounting Services Ltd | Professional & scientific | 2009 |
| Knightwood Homes Limited | Real estate | 2021 |
| Knightwood Legal (Global Consulting) Ltd | Transport & logistics | 2004 |
| Knot Just Blooms Limited | Wholesale & retail | 2018 |
| Knowhowuk LLP | | 2012 |
| KNP Homes Limited | Real estate | 2024 |
| Koala Cabinets (Australian Sewing Stations) Ltd | Extraterritorial | 1999 |
| Kogo Productions Limited | Arts & recreation | 2014 |
| Korb Hampers UK Ltd | Wholesale & retail | 2025 |
| Koshka Consultancy Ltd | Information & communication | 2012 |
| KP Horizons Engineering Ltd | Construction | 2011 |
| KP Social Ltd | Professional & scientific | 2025 |
| KP Structural Consultants Ltd | Professional & scientific | 2016 |
| Kpe&S Limited | Professional & scientific | 2017 |
| KPI Management Controls Limited | Other services | 2023 |
| KR Tourism Ltd | Administrative & support | 2013 |
| Kraferd Limited | Information & communication | 2015 |
| Kriash Stores Limited | Wholesale & retail | 2022 |
| Krish Software Solutions Limited | Information & communication | 2015 |
| Krisha News Ltd | Wholesale & retail | 2025 |
| Kristruck Ltd | Transport & logistics | 2014 |
| Kroot Holdings Limited | Financial services | 2024 |
| Kroot Medical Solutions Ltd | Health & social care | 2023 |
| Krowdkast Ltd | Information & communication | 2018 |
| KRS Residential Developments Ltd | Real estate | 2016 |
| KRS Retail Ltd | Construction | 2008 |
| Krupa Accounting Limited | Professional & scientific | 2020 |
| Krystal Diamonds Ltd | Wholesale & retail | 2018 |
| Ksimc Investments Ltd | Real estate | 2015 |
| Ksimc Residential Investments Ltd | Real estate | 2017 |
| Kskb Ltd | Administrative & support | 2022 |
| KSL Accounting Services Ltd | Professional & scientific | 2026 |
| KTM Keska Ltd | Transport & logistics | 2015 |
| Kuala Estates Ltd | Real estate | 2019 |
| Kunashe Care Ltd | Administrative & support | 2024 |
| Kunex Consulting Limited | Administrative & support | 2022 |
| KV Plumbing & Heating Ltd | Construction | 2020 |
| Kvtr PVT Ltd | Wholesale & retail | 2019 |
| Kwackers Limited | Hospitality | 2021 |
| Kwackers West Quay Limited | Hospitality | 2023 |
| KXC Properties Ltd | Construction | 2025 |
| Kyrle Properties Ltd | Administrative & support | 2009 |
| L & H Property Solutions Limited | Households | 2018 |
| L E H Investments Limited | Real estate | 2021 |
| L E S Events Limited | Real estate | 2013 |
| L G Installations Ltd | Construction | 2013 |
| L J Smith Family Butchers Limited | Manufacturing | 2003 |
| L West Plastering Ltd | Construction | 2023 |
| L&A Transports Ltd | Transport & logistics | 2018 |
| L.A. Dog Grooming Limited | Other services | 2018 |
| L.A.Brickwork. Ltd | Construction | 2013 |
| L.M.V. Universal Ltd | Transport & logistics | 2014 |
| LA Contract Services Limited | Manufacturing | 2025 |
| LA Medicine Ltd | Wholesale & retail | 2024 |
| LA Nails 2025 Ltd | Other services | 2025 |
| Laban Consult UK Ltd | Professional & scientific | 2022 |
| Lacuna Projects Ltd | Manufacturing | 2019 |
| Ladher Homes Limited | Real estate | 2024 |
| Ladycroft Farm Ltd | Construction | 2025 |
| Lake Avenue Property Management Limited | Households | 2002 |
| Lakewood Homes Ltd | Real estate | 2023 |
| Land Building Services Ltd | Construction | 2014 |
| Land Consult LLP | | 2014 |
| Landa Wealth and Property Ltd | Real estate | 2017 |
| Lane Financial Management Limited | Financial services | 2001 |
| Langdowns DFK Limited | Professional & scientific | 2006 |
| Langdowns Limited | Professional & scientific | 1989 |
| Langford Asset Group Limited | Real estate | 2022 |
| Langstone Properties Limited | Real estate | 2022 |
| Language Class Ltd | Education | 2019 |
| Language Studio Limited | Education | 2018 |
| Lanna Spa Limited | Other services | 2015 |
| Lapd Homes Limited | Real estate | 2022 |