| KEP81 Ltd | Construction | 2022 |
| Kernow Registered Foot Health Practitioners Limited | Health & social care | 2025 |
| Kesar Iqbal Ltd | Health & social care | 2025 |
| Ketton Power & Safety Ltd | Manufacturing | 2023 |
| Keudos Clean Ltd | Administrative & support | 2023 |
| Keudos Connect Recruitment Services Ltd | Administrative & support | 2025 |
| Kevin Bennett Ltd | Education | 2024 |
| Kevin Flower (Purchasing Consultant) Limited | Professional & scientific | 2024 |
| Kevin Mayhew Holdings Limited | Information & communication | 1996 |
| Kevin Mayhew Limited | Information & communication | 1976 |
| Key Connection Development Services Ltd | Information & communication | 2018 |
| Keychain Property Solutions Ltd | Real estate | 2023 |
| Keypalm Ltd | Administrative & support | 2023 |
| Keyson Ltd | Real estate | 2019 |
| Keystone Global Capital & Administrative Services Ltd | Professional & scientific | 2015 |
| Keystone Rentals Ltd | Real estate | 2026 |
| Keystone Technologies Ltd | Information & communication | 2026 |
| KF Graham Engineering Limited | Manufacturing | 2026 |
| KG Biostrategy Ltd | Professional & scientific | 2026 |
| KG Convenience Store Ltd | Wholesale & retail | 2020 |
| KGF Commerce Ltd | Wholesale & retail | 2023 |
| KGI Software Ltd | Information & communication | 2026 |
| KGT Security Ltd | Administrative & support | 2026 |
| KH Taxi Newmarket Limited | Wholesale & retail | 2024 |
| Khaki Devil Limited | Other services | 2001 |
| Khalsa Saffron Ltd | Agriculture & fishing | 2025 |
| Khan Cyber Sales Ltd | Wholesale & retail | 2024 |
| Khan's Global Services Ltd | Information & communication | 2025 |
| Khatec Ltd | Administrative & support | 2023 |
| Khemsburg UK Ltd | Wholesale & retail | 2024 |
| Khoh Brothers Ltd | Wholesale & retail | 2025 |
| KI Tech Limited | Information & communication | 2016 |
| Ki-Nitro Collective Ltd | Transport & logistics | 2020 |
| Kiandra Ltd | Construction | 2014 |
| Kicks Academy -Professional Development Ltd | Professional & scientific | 2019 |
| Kickz&Bitz Limited | Wholesale & retail | 2026 |
| Kiddys Ltd | Wholesale & retail | 2025 |
| Kidibeds Ltd | Wholesale & retail | 2020 |
| Kidszone Adventures Ltd | Education | 2019 |
| Kieranghw Ltd | Construction | 2022 |
| Kiin Partnership Limited | Professional & scientific | 2026 |
| Kimchi With Everything Ltd | Manufacturing | 2020 |
| Kimini Ltd | Wholesale & retail | 2019 |
| Kindle Light Health Care Services Limited | Health & social care | 2023 |
| Kindled Limited | Other services | 2026 |
| Kineasis Consulting Ltd | Information & communication | 2026 |
| Kinetic Solutions (UK) Limited | Construction | 2002 |
| Kinexus Trading Limited | Wholesale & retail | 2017 |
| King Cleaning Services T/A Dolly Char Leicester Ltd | Administrative & support | 2025 |
| King's Permanent Buildings Limited | Construction | 1954 |
| Kingdom Global Real Estate Ltd | Real estate | 2023 |
| Kingdom Tree Limited | Financial services | 2022 |
| Kingham Media Solutions Ltd | Manufacturing | 2026 |
| Kings Crescent Ltd | Construction | 2012 |
| Kings Flooring Systems Ltd | Construction | 2019 |
| Kings Groundworks Limited | Other services | 2003 |
| Kings Langley Badminton Club Ltd | Arts & recreation | 2026 |
| Kings Mews (Bury ST Edmunds) Management Company Limited | Households | 2006 |
| Kingshall Street Management Company Limited | Households | 2025 |
| Kinsey Mcbain Capital Management Ltd | Financial services | 2024 |
| Kinship Press Ltd | Manufacturing | 2018 |
| Kintela Ltd | Wholesale & retail | 2024 |
| Kintye Ltd | Wholesale & retail | 2023 |
| KIO Trading Limited | Wholesale & retail | 2025 |
| Kionier Ltd | Information & communication | 2019 |
| Kipm Limited | Professional & scientific | 2015 |
| Kirabo GRC Solutions Limited | Professional & scientific | 2023 |
| Kiro Ltd | Administrative & support | 2026 |
| Kirsten Goodwin Coaching Limited | Other services | 2019 |
| Kirsty Joanna Fitness Ltd | Other services | 2020 |
| Kirwin Maclean Associates Ltd | Health & social care | 2006 |
| Kiss My Pampas Ltd | Wholesale & retail | 2021 |
| Kitchen Ventures Ltd | Hospitality | 2020 |
| Kitchenlux Ltd | Administrative & support | 2025 |
| Kitchenstuff Ltd | Wholesale & retail | 2022 |
| Kitebrook Capital Ltd | Financial services | 2020 |
| Kitpad Ltd | Information & communication | 2014 |
| Kitt Creative Ltd | Information & communication | 2026 |
| Kixxstar Limited | Information & communication | 2023 |
| KJA Asset Trading Ltd | Wholesale & retail | 2026 |
| Kjcreative Limited | Administrative & support | 2015 |
| KJD Holiday LET Managment Ltd | Hospitality | 2024 |
| KJK Rentals Limited | Other services | 2026 |
| KK Consultancy and Accounting Ltd | Administrative & support | 2013 |
| KK Family Holdings Ltd | Financial services | 2026 |
| KK Holdco Limited | Financial services | 2024 |
| KK ME Ltd | Information & communication | 2025 |
| KK360 Plant Operating Limited | Construction | 2016 |
| KL Data Ltd | Information & communication | 2026 |
| KL Resource Limited | Information & communication | 2000 |
| KL Vehicle Trade Ltd | Wholesale & retail | 2025 |
| Klasiqa Limited | Wholesale & retail | 2023 |
| Klein Defence Consulting Ltd | Professional & scientific | 2024 |
| Kleverideas Limited | Wholesale & retail | 2006 |
| Kliktronic Limited | Manufacturing | 1998 |
| Klimbe Limited | Education | 2024 |
| Klivo Ltd | Wholesale & retail | 2026 |
| Klondyke Allotment Association CIC | Agriculture & fishing | 2016 |
| Kloud Bucket Ltd | Information & communication | 2025 |
| Klouddap Solutions Ltd | Information & communication | 2021 |