| Kathea Ltd | Health & social care | 2025 |
| Kaur Roots Ltd | Real estate | 2025 |
| Kayanis Bistro Group Ltd | Wholesale & retail | 2023 |
| Kaylia Services Limited | Hospitality | 2025 |
| KB & B Financial Services Limited | Financial services | 2026 |
| KB & B Technical Services Limited | Manufacturing | 2015 |
| KB Control Systems Limited | Information & communication | 2024 |
| KB Euro Food Ltd | Wholesale & retail | 2025 |
| KB Props Limited | Arts & recreation | 2021 |
| KBS Lettings Ltd | Real estate | 2025 |
| KC Cosmetics Ltd | Other services | 2020 |
| KC Flanagan Limited | Other services | 2018 |
| KC Hogan Business Services Limited | Professional & scientific | 2018 |
| Kcig Associates Limited | Professional & scientific | 2020 |
| KCT Supplies Limited | Wholesale & retail | 2012 |
| KD Construction Consultants Ltd | Construction | 2024 |
| KD Smart Solutions Ltd | Wholesale & retail | 2025 |
| KDA Accountants Ltd | Information & communication | 2017 |
| KDA Bookkeeping Services Limited | Professional & scientific | 2019 |
| KDA Property Services Ltd | Real estate | 2025 |
| KDW Properties Ltd | Real estate | 2025 |
| KE H and S Ltd | Health & social care | 2026 |
| Kedar Foods Ltd | Hospitality | 2023 |
| Kedia Estates Ltd | Real estate | 2023 |
| KEE Process Limited | Manufacturing | 1955 |
| KEE Services Limited | Water & waste | 2004 |
| Keemtop Limited | Real estate | 2023 |
| Keen's Domestic Appliances Limited | Wholesale & retail | 2006 |
| Keene Capital | Administrative & support | 2019 |
| Keenness London Limited | Wholesale & retail | 2024 |
| Keep Kleen (Oxon) Ltd | Administrative & support | 2008 |
| Keepers Cottage Services Limited | Wholesale & retail | 2017 |
| Keepers Pest Control Ltd | Agriculture & fishing | 2017 |
| Keff Meyler Ltd | Professional & scientific | 2020 |
| Keith Elliott Limited | Professional & scientific | 2025 |
| Keith Mckay Ltd | Construction | 2003 |
| Kelltron Consulting Services UK Ltd | Information & communication | 2015 |
| Kelltron Software Solutions Ltd | Information & communication | 2025 |
| Kelly Plus Limited | Professional & scientific | 2024 |
| Keloo Transport Ltd | Transport & logistics | 2016 |
| Kelotech Ltd | Information & communication | 2019 |
| Kempson Electrical Services Limited | Construction | 1997 |
| Kendra Rooms Limited | Hospitality | 2018 |
| Kendra Security Limited | Administrative & support | 2023 |
| Kenilworth Homes Ltd | Health & social care | 2026 |
| Kepler Consulting Limited | Professional & scientific | 2023 |
| Kerbsafe Franchising Limited | Wholesale & retail | 2018 |
| Kerbsafe Limited | Wholesale & retail | 2011 |
| Kerbsafe Wheel Repair Limited | Wholesale & retail | 2018 |
| Keshri Process Solutions Limited | Professional & scientific | 2017 |
| Kessy Kayla Limited | Wholesale & retail | 2025 |
| Kestrel Aviation Ltd | Professional & scientific | 2022 |
| Kevin Mustard Associates Limited | Administrative & support | 2013 |
| Kevin Payne Interiors Ltd | Construction | 2018 |
| Key Gardencare Ltd | Administrative & support | 2005 |
| Keykeeper Solutions Limited | Information & communication | 2014 |
| Keypersonnel Services Limited | Administrative & support | 2021 |
| Keystone Residential Housing Ltd | Real estate | 2025 |
| KF HR Services Ltd | Professional & scientific | 2019 |
| KG Healthcare Ltd | Health & social care | 2025 |
| KG Insure Ltd | Other services | 2017 |
| KGB Creative Limited | Information & communication | 2014 |
| Kgrmk Consultancy Limited | Information & communication | 2018 |
| KH Infosec Ltd | Information & communication | 2017 |
| Khalil Services Limited | Construction | 2025 |
| Kharadi Enterprise Ltd | Wholesale & retail | 2025 |
| Khatalyst Ltd | Financial services | 2018 |
| Khatri & Sons Real Estates Ltd | Real estate | 2022 |
| Khattak Properties Limited | Construction | 2024 |
| Khimel Management Ltd | Information & communication | 2019 |
| Khoya Mithai Ltd | Manufacturing | 2021 |
| Khyber Transport Ltd | Transport & logistics | 2024 |
| KI Engineering Ltd | Construction | 2024 |
| Kiarazane Limited | Wholesale & retail | 2026 |
| Kiddies Blossom Limited | Health & social care | 2025 |
| Kiengs IT Limited | Construction | 2015 |
| Kifkim Corporate Services Ltd. | Professional & scientific | 2014 |
| Kiki London Ltd | Other services | 2021 |
| Kimble Communications Limited | Professional & scientific | 2014 |
| Kimble Oak Limited | Construction | 2025 |
| Kimble Pasture Ltd | Agriculture & fishing | 2010 |
| Kimble Turning Ltd | Manufacturing | 2025 |
| Kimblewick Properties Limited | Real estate | 1954 |
| Kincardine Investments Limited | Real estate | 2020 |
| Kindell Properties Ltd | Extraterritorial | 2020 |
| Kinderworks Ltd | Professional & scientific | 2021 |
| Kinell Investments Limited | Real estate | 2022 |
| King Issachar Records Ltd | Information & communication | 2011 |
| Kingdom Life Assemblies of GOD Ltd | Other services | 2019 |
| Kingdom Values Limited | Manufacturing | 2004 |
| Kingdon Developments Limited | Construction | 2010 |
| Kingdon Group Ltd | Administrative & support | 2022 |
| Kings ASH Interiors Ltd | Construction | 2025 |
| Kings League Records Limited | Information & communication | 2025 |
| Kingsbrook Dental Ltd | Health & social care | 2023 |
| Kingsbrook Joinery Holdings Ltd | Manufacturing | 2019 |
| Kingsbrook Joinery Ltd | Manufacturing | 2019 |
| Kingsgate RTM Company Limited | Households | 2014 |
| Kingsland Carpentry Limited | Construction | 2007 |
| Kingsley Partners Limited | Manufacturing | 2011 |