| Knowledgeworks Global UK Limited | Information & communication | 2003 |
| Knoydart Brewery Limited | Manufacturing | 2015 |
| KNV Investment Limited | Real estate | 2021 |
| Koders Technology Ltd | Information & communication | 2016 |
| Kojo Marfo Studio Ltd | Arts & recreation | 2024 |
| Kommuru Technologies Ltd | Information & communication | 2017 |
| Kompassion Ltd | Manufacturing | 2018 |
| Konese Landscape Ltd | Administrative & support | 2025 |
| Konku Care (Sutton) Limited | Financial services | 2023 |
| Konku Care Limited | Financial services | 2023 |
| Konku Developers Ltd | Construction | 2020 |
| Koora Coaching Limited | Education | 2024 |
| Kosebasi Putney Limited | Hospitality | 2019 |
| Kosmo Group Ltd | Construction | 2022 |
| Kostov Telecom Ltd | Construction | 2015 |
| Kotex Venture Limited | Transport & logistics | 2011 |
| Kounoupias IP Limited | Professional & scientific | 2007 |
| Kovai Consulting Limited | Information & communication | 2018 |
| Kovit Santhai Ltd | Wholesale & retail | 2013 |
| Kovo Limited | Wholesale & retail | 2025 |
| KP Decorating Home Improvements Ltd | Construction | 2014 |
| KP Premium Body Work Ltd | Wholesale & retail | 2025 |
| Kpfp EOT Limited | Administrative & support | 2024 |
| Kpfp Ltd | Construction | 2003 |
| KR Sabers Limited | Manufacturing | 2014 |
| Krasi Dinev Ltd | Construction | 2018 |
| Kraze Toys Ltd | Wholesale & retail | 2025 |
| KRD Property Management Services Ltd | Households | 2026 |
| Krem Design Limited | Hospitality | 2020 |
| Kremeecakes Limited | Hospitality | 2020 |
| Krisam Ltd | Construction | 2015 |
| Krishlahar Ltd | Hospitality | 2020 |
| Krishna Restaurant Ltd | Hospitality | 2025 |
| Kristianphillipsconsultancy Ltd | Construction | 2020 |
| Krititek Limited | Information & communication | 2015 |
| Kroki Limited | Manufacturing | 2023 |
| Krollnikstar Ltd | Hospitality | 2025 |
| Kroud Ltd | Financial services | 2025 |
| Kroud Renewables Ltd | Construction | 2025 |
| Kroud Solutions Ltd | Construction | 2025 |
| Kroud Tech Ltd | Information & communication | 2025 |
| KRY Consultants Ltd | Professional & scientific | 2025 |
| Krystal DRY Cleaners Ltd | Other services | 2013 |
| Kryswindows Ltd | Administrative & support | 2019 |
| KS Construct Recruit Ltd | Construction | 2024 |
| KS Sutton Limited | Hospitality | 2012 |
| KSG Solutions Ltd | Other services | 2016 |
| KSQ IT Consulting Ltd | Information & communication | 2012 |
| KT120 Limited | Wholesale & retail | 2024 |
| KU Estates Ltd | Real estate | 2022 |
| Kudemi Ltd | Information & communication | 2012 |
| Kudos Remarketing Limited | Information & communication | 2007 |
| Kuldeep Enterprises Ltd | Wholesale & retail | 2021 |
| Kumaran Brothers Limited | Hospitality | 2024 |
| Kumarasamy Property Ltd | Real estate | 2025 |
| Kumon Tooting Ltd | Education | 2023 |
| KUN Builder Ltd | Construction | 2022 |
| Kuruppriya Properties Ltd | Real estate | 2022 |
| Kutukcu Catering Limited | Hospitality | 2025 |
| KVG Investments Ltd | Wholesale & retail | 2014 |
| KYG Service & Co Limited | Professional & scientific | 2015 |
| Kylie's Nails Ltd | Other services | 2018 |
| L & M Colucci Ltd | Construction | 2023 |
| L & S Estates Limited | Real estate | 2019 |
| L C S Plumbing & Heating Services Ltd | Construction | 2026 |
| L F Airport Transfers Ltd | Transport & logistics | 2022 |
| L Gajda Consulting Ltd | Professional & scientific | 2018 |
| L S Catering Ltd | Hospitality | 2018 |
| L V R I Limited | Real estate | 2018 |
| L&D Health Ltd | Professional & scientific | 2025 |
| L&F Avenue Ltd | Wholesale & retail | 2025 |
| L&G Contractors Ltd | Construction | 2008 |
| L&H Holborn Limited | Hospitality | 2019 |
| L&H Motor Mechanics Ltd | Wholesale & retail | 2019 |
| L&L Property Consultants Limited | Professional & scientific | 2023 |
| L&S Scenery Ltd | Construction | 2024 |
| L&T Accountancy & Financial Advisors Limited | Wholesale & retail | 2025 |
| L'Seabed Ventures Ltd | Administrative & support | 2014 |
| L. B. Electrical Services Limited | Construction | 2016 |
| L. C. Dove Limited | Wholesale & retail | 2026 |
| L.A Nails Bar Ltd | Other services | 2026 |
| L.D Heating Solutions Ltd | Construction | 2021 |
| L.J.Laing Limited | Real estate | 1972 |
| L.L Rigging Ltd | Construction | 2021 |
| LA Cafe Fine Foods Limited | Hospitality | 2021 |
| LA Sicilia Ltd | Hospitality | 2024 |
| Laayoune Ltd | Construction | 2018 |
| LAB2LEGACY Ltd | Information & communication | 2025 |
| Label Construction Ltd | Construction | 2024 |
| Labhsethu Ltd | Professional & scientific | 2025 |
| Lacey’S Upholstery Ltd | Other services | 2025 |
| Ladybird Learners Ltd | Health & social care | 2025 |
| Laedi Limited | Real estate | 2025 |
| Lagan Consulting Ltd | Information & communication | 2022 |
| Lahore Eastcote Trading Limited | Hospitality | 2019 |
| Lahore Restaurant (London) Limited | Administrative & support | 2017 |
| Laidlaw Electrical Limited | Construction | 2001 |
| Laidlaw Legal Ltd | Professional & scientific | 2024 |
| Laione Ltd | Extraterritorial | 2024 |
| Lakas Housing Ltd | Real estate | 2021 |