| Key Education Consultants Ltd | Professional & scientific | 2020 |
| Key Group Services Limited | Professional & scientific | 2006 |
| Key Safety Solutions Limited | Extraterritorial | 2017 |
| Key Steering Systems Limited | Manufacturing | 1982 |
| Key Stone Edge 5D Limited | Wholesale & retail | 2024 |
| Key Stone Horizons Ltd | Construction | 2025 |
| Key Team Ltd | Other services | 2026 |
| Keylu Ltd | Information & communication | 2008 |
| Keyrooms Community Interest Company | Real estate | 2025 |
| Keys Auctioneers Limited | Wholesale & retail | 2012 |
| Keys Kitchen (Aylsham) Ltd | Hospitality | 2026 |
| Keystone Corporate Relocations Limited | Hospitality | 2024 |
| Keyword Ventures Ltd | Information & communication | 2024 |
| Kfoodtech Services Limited | Professional & scientific | 2002 |
| KG Offshore Limited | Mining & quarrying | 2019 |
| KGB Commercial Heating Limited | Manufacturing | 2008 |
| KGF Engineering Ltd | Wholesale & retail | 2021 |
| Kgls Properties Limited | Real estate | 2025 |
| KGS Management Ltd | Professional & scientific | 2019 |
| KH Digital Ltd | Information & communication | 2018 |
| KH Hospitalities Limited | Hospitality | 2023 |
| KH Lease Holding Ltd | Real estate | 2015 |
| Khachan Engineering Ltd | Professional & scientific | 2018 |
| Khair Services Limited | Wholesale & retail | 2025 |
| Khajwal & Company Ltd | Health & social care | 2013 |
| Khalil Building Ltd | Construction | 2023 |
| Khan Deliverry Service Ltd | Transport & logistics | 2020 |
| Khan Services Ltd | Administrative & support | 2017 |
| Khans of Carlisle Limited | Real estate | 2017 |
| Khanzz Ltd | Hospitality | 2019 |
| Kharroubi Ltd | Transport & logistics | 2024 |
| Khcc Holdings Ltd | Professional & scientific | 2024 |
| KHG Accounts Ltd | Professional & scientific | 2025 |
| KHG Services Ltd | Arts & recreation | 2023 |
| Khimuk Restaurant Limited | Hospitality | 2019 |
| Khongmanee Limited | Hospitality | 2019 |
| Khproperty Ltd | Real estate | 2022 |
| Khra Ltd. | Wholesale & retail | 2015 |
| Khyber Grill Birmingham Ltd | Hospitality | 2019 |
| Kibodya Annex Limited | Extraterritorial | 2019 |
| Kickback Kitchens CIC | Hospitality | 2023 |
| Kickback Tax Ltd | Professional & scientific | 2013 |
| Kickdish Ltd | Information & communication | 2018 |
| Kickxfootball Ltd | Arts & recreation | 2021 |
| Kiddway UK Ltd | Professional & scientific | 2015 |
| Kidmans Paint and Detail Limited | Wholesale & retail | 2013 |
| Kidner Farming Limited | Agriculture & fishing | 1947 |
| Kieft & Sons Limited | Wholesale & retail | 1933 |
| Kieran Dunphy Criminal Defence Solicitor Ltd | Professional & scientific | 2024 |
| Kieran Looney & Co Ltd. | Professional & scientific | 2009 |
| Kiki Distribution Ltd | Administrative & support | 2014 |
| Kiki Health Ltd | Administrative & support | 2013 |
| Kiki Limited | Wholesale & retail | 1999 |
| Kikis. Services Ltd | Hospitality | 2020 |
| KIL Rental Limited | Real estate | 2024 |
| Kilburn Park (AR) Limited | Real estate | 2018 |
| Kilda Services (Norfolk) Ltd | Other services | 2014 |
| Kilgannon Street Care Group Limited | Construction | 2019 |
| Kilimanjaro Ventures Ltd | Professional & scientific | 2018 |
| Killyon Holdings Ltd | Financial services | 2021 |
| Killyon Properties Ltd | Real estate | 2018 |
| Kiln Cliff (Mundesley) Limited | Hospitality | 1950 |
| Kilo Charlie Ltd | Transport & logistics | 2024 |
| Kilsyth Limited | Agriculture & fishing | 2010 |
| Kilverton Limited | | 1991 |
| KIM Uzzell Consulting Ltd | Other services | 2020 |
| KIM Woodrow Limited | Professional & scientific | 2003 |
| Kima Enterprises Limited | Hospitality | 2025 |
| Kimber Advisory Ltd | Professional & scientific | 2025 |
| Kimberley Electrical Services Ltd | Construction | 2020 |
| Kimberley Farms Limited | Agriculture & fishing | 1947 |
| Kimberley Property Management Limited | Households | 2021 |
| Kimberley Radiology Ltd | Health & social care | 2020 |
| Kimberley Trading Ltd | Wholesale & retail | 2025 |
| Kimble Consulting Ltd | Professional & scientific | 2015 |
| Kimeriya Ltd | Professional & scientific | 2011 |
| Kin-Nuga Limited | Other services | 2019 |
| Kinda Education C.I.C. | Education | 2018 |
| Kindfisher Limited | Hospitality | 2025 |
| Kindlycare at Home Ltd | Administrative & support | 2026 |
| Kindroots Childrens Care Ltd | Education | 2026 |
| Kinetic Hosting Ltd | Information & communication | 2026 |
| KINETIC7 Technologies UK Limited | Health & social care | 2020 |
| King & Co Developments Ltd | Construction | 2025 |
| King and Company (Norfolk) Limited | Construction | 2017 |
| King and Company Developments Limited | Construction | 2019 |
| King and Company Holdings Ltd | Financial services | 2024 |
| King Pipework & Fabrication Services Ltd | Manufacturing | 2021 |
| King Street (Norwich) Residents Association Limited | Real estate | 2016 |
| King's Summer Homes Limited | Hospitality | 1961 |
| Kingdom Spas and Hot Tubs Limited | Wholesale & retail | 2012 |
| Kinge Farm Services Ltd | Agriculture & fishing | 2025 |
| Kingfisher Advisory Ltd | Professional & scientific | 2025 |
| Kingfisher Ceramics Ltd | Health & social care | 2010 |
| Kingfisher Decorators Limited | Construction | 2016 |
| Kingfisher Natural Toothpaste Limited | Wholesale & retail | 2025 |
| Kingfisher Recruitment Limited | Administrative & support | 2007 |
| Kingfisher Rentals Ltd | Real estate | 2021 |
| Kingfisher Schools Trust | Education | 2011 |
| Kings & Dunne Architects Ltd | Professional & scientific | 2018 |