| Kakkar Investments Limited | Real estate | 2021 |
| Kaleb Partners Ltd | Wholesale & retail | 2021 |
| Kally's Cakes Limited | Hospitality | 2009 |
| Kalyani Transmission Technologies International Limited | Wholesale & retail | 2020 |
| Kalyani Transmission Technologies Limited | Manufacturing | 2018 |
| Kandy Services Ltd | Administrative & support | 2021 |
| Kanmore Investments Limited | Administrative & support | 2023 |
| Kansagra Investment Group Ltd | Real estate | 2021 |
| Kantec Project Management Ltd | Administrative & support | 2012 |
| Kaosarn Ltd | Hospitality | 2024 |
| Kaoska Group Limited | Administrative & support | 2013 |
| Kaoska Properties Management Ltd | Extraterritorial | 2024 |
| KAP Global Ltd | Information & communication | 2018 |
| Karan Foods Limited | Wholesale & retail | 2024 |
| Karen Fardell & Associates Ltd | Professional & scientific | 1997 |
| Karenay Diamond Limited | Wholesale & retail | 2025 |
| Karma Bros Ltd | Information & communication | 2017 |
| Karma Consult Limited | Professional & scientific | 2021 |
| Karma Investment Properties Limited | Real estate | 2018 |
| Karmin Services Limited | Information & communication | 2018 |
| Kartzhub Limited | Information & communication | 2017 |
| Kary Ceilings Limited | Construction | 2019 |
| Katherine Wilson Limited | Health & social care | 2019 |
| Katkon (UK) Limited | Professional & scientific | 2007 |
| Kazmi Corporation Ltd | Wholesale & retail | 2024 |
| KB Hair and Beauty Ltd | Other services | 2022 |
| KB Holdings India Limited | Real estate | 2019 |
| KBC Technologies UK Limited | Information & communication | 2022 |
| KC Music Productions Ltd | Information & communication | 2024 |
| KD Whisker Limited | Real estate | 2019 |
| Keads Production Limited | Information & communication | 2017 |
| Kedgeree Design Ltd | Wholesale & retail | 2025 |
| Keen Tuition Ltd | Education | 2017 |
| Keepad International Ltd | Information & communication | 2016 |
| Kemispray Ltd | Manufacturing | 2022 |
| Kendall Mediation Limited | Other services | 2022 |
| Kenmore Hospitality Ltd | Financial services | 2022 |
| Kenmore Hotel Holdings Ltd | Financial services | 2022 |
| Kenmore Residential Ltd | Financial services | 2021 |
| Kensington Hounds Ltd | Wholesale & retail | 2019 |
| Kensington Wholesale Ltd | Wholesale & retail | 2025 |
| Kerry Haynes Ltd | Professional & scientific | 2022 |
| Kerygma 180 | Other services | 2008 |
| KEW Bridge Engines Trust and Water Supply Museum Limited(The) | Arts & recreation | 1974 |
| KEW Bridge Travel Limited | Administrative & support | 2019 |
| KEW Estate Agents Ltd | Real estate | 2019 |
| Key Facilities Engineering Limited | Construction | 2025 |
| Key Point Agency Ltd | Administrative & support | 2017 |
| Keys for ALL Limited | Real estate | 2020 |
| Keysen Accountancy Limited | Professional & scientific | 2024 |
| Keystone Hospitality Compliance Ltd. | Professional & scientific | 2025 |
| Keystone Monitoring Ltd | Real estate | 2026 |
| KF Solutions Limited | Information & communication | 2014 |
| KG Motor Services Ltd | Wholesale & retail | 2015 |
| KH Asbestos Investigations Limited | Professional & scientific | 2009 |
| KH Landseeka Limited | Extraterritorial | 2002 |
| Kh&N Constructions Limited | Construction | 2021 |
| Khalid Constructions Ltd | Construction | 2016 |
| Khosa Services Ltd | Households | 2023 |
| Khoshi Global Ltd | Administrative & support | 2025 |
| KHP Securities Limited | Professional & scientific | 2002 |
| KHV Concept Ltd | Wholesale & retail | 2021 |
| Kickback Circle Ltd | Arts & recreation | 2026 |
| Kindam Properties Limited | Real estate | 2021 |
| Kindtails Limited | Manufacturing | 2025 |
| Kings Analytica Ltd | Information & communication | 2021 |
| Kingsden Group Ltd | Real estate | 2022 |
| Kingston Scaffolding Ltd | Construction | 2024 |
| Kingworths Ltd | Real estate | 2022 |
| Kinngs Services Ltd | Construction | 2022 |
| Kirby Group Engineering (UK) Limited | Professional & scientific | 2007 |
| Kirk Data Analytics Ltd | Information & communication | 2023 |
| Kirpa Medical Limited | Health & social care | 2020 |
| Kitpool Collective Ltd | Administrative & support | 2025 |
| KJ Learning Limited | Professional & scientific | 2009 |
| KJ Services Group Ltd | Construction | 2025 |
| KJP Construction Limited | Construction | 2010 |
| KL Build Ltd | Administrative & support | 2017 |
| Klear Financials Limited | Financial services | 2017 |
| Klothes Restorers Ltd | Other services | 2023 |
| Kloudjs Limited | Information & communication | 2021 |
| KM Accountancy Services Ltd | Professional & scientific | 2013 |
| KM Commercial Finance Limited | Professional & scientific | 2018 |
| Kmechz Limited | Wholesale & retail | 2013 |
| KMV Consulting Ltd | Professional & scientific | 2025 |
| Knapp Hicks and Partners Limited | Professional & scientific | 1994 |
| Knightlord Limited | Wholesale & retail | 2009 |
| Knights Financial Consulting Ltd | Information & communication | 2014 |
| Knowledge TAP Ltd | Information & communication | 2023 |
| Koactt Limited | Extraterritorial | 2021 |
| KOG Promotions Ltd | Information & communication | 2020 |
| KOL Limited | Information & communication | 2009 |
| Konzeption West Ltd | Information & communication | 2014 |
| Koolvix Global Limited | Manufacturing | 2025 |
| Koonde Limited | Wholesale & retail | 2022 |
| Kosli Limited | Information & communication | 2021 |
| Kotak IT Limited | Information & communication | 2021 |
| KR London Builders and Demolition Ltd | Real estate | 2022 |
| Kris Technologies Ltd | Information & communication | 2012 |
| Krish Capital Ventures Limited | Financial services | 2025 |