| K&S Security Installations Limited | Administrative & support | 2010 |
| K-3 Civils Ltd | Construction | 2023 |
| K. Hankinson (Painter & Decorators) Limited | Construction | 2003 |
| K. W. Catering Ltd | Hospitality | 2015 |
| K.A.Parker Ltd | Real estate | 2025 |
| K.D.B. Services Limited | Construction | 2004 |
| K2 Electrical Ltd | Construction | 2025 |
| K2 Equity Partners LLP | | 2006 |
| K4 Management Ltd | Construction | 2023 |
| K9 Retreat Limited | Extraterritorial | 2020 |
| Kabod Analytics Limited | Information & communication | 2019 |
| Kabod Place Enterprise Ltd | Information & communication | 2010 |
| Kaczor Solutions Limited | Wholesale & retail | 2024 |
| Kadant U.K. Limited | Manufacturing | 1983 |
| Kadant UK Holdings Limited | Professional & scientific | 2003 |
| KAE Estates Ltd | Administrative & support | 2026 |
| KAM Lung Ltd | Transport & logistics | 2026 |
| Kamlabelz Ltd | Wholesale & retail | 2020 |
| Kamm Trading Limited | Wholesale & retail | 2008 |
| Kampo Consulting Ltd | Construction | 2023 |
| Kandy Kraze Bury Ltd | Hospitality | 2021 |
| Kanes Group Ltd | Real estate | 2023 |
| Kanes Partnerships Limited | Construction | 2024 |
| Kanonika Limited | Professional & scientific | 2013 |
| Kanootesoft Ltd | Information & communication | 2020 |
| Kanso Motors Ltd | Wholesale & retail | 2017 |
| Kapow Marketing Communications Group Limited | Professional & scientific | 1997 |
| Kareem Ltd | Hospitality | 2018 |
| Karinda Ltd | Construction | 2025 |
| Karl the Builder Ltd | Construction | 2020 |
| Karlowe Psychological Services Limited | Health & social care | 2016 |
| Karma Living Limited | Administrative & support | 2006 |
| Kashi Investments Limited | Wholesale & retail | 2020 |
| Kashmir OIL Limited | Water & waste | 2023 |
| Katie Gael Aldrich Limited | Extraterritorial | 2024 |
| Katie Gael Milnes Limited | Extraterritorial | 2024 |
| Katie Malley Ltd | Education | 2024 |
| Katre Property Ltd | Real estate | 2025 |
| Katsouris Delicatessen Limited | Wholesale & retail | 2003 |
| KAY Brow Management Co. Limited | Administrative & support | 1976 |
| KAY Brow Tyres and Exhausts Ltd | Wholesale & retail | 2012 |
| Kaybrook Capital Ltd | Wholesale & retail | 2015 |
| Kaycliffe Ltd | Construction | 2013 |
| Kaytu Limited | Wholesale & retail | 2023 |
| Kaz's Convenience Store Ltd | Wholesale & retail | 2023 |
| Kban Logistics Ltd | Transport & logistics | 2025 |
| KBC Retail Ventures Ltd | Wholesale & retail | 2025 |
| KBS Team Ltd | Information & communication | 2026 |
| KC Building Services (N/W) Ltd | Construction | 2006 |
| KD Foods Limited | Wholesale & retail | 2024 |
| KD Safeguarding Ltd | Education | 2016 |
| KDB Projects Limited | Financial services | 2020 |
| Kdog Kennedy Ltd | Construction | 2015 |
| KDW Training Limited | Education | 2017 |
| KEA Contracts Limited | Construction | 2010 |
| Keane Games Ltd | Information & communication | 2016 |
| Keane HR Consulting Ltd | Administrative & support | 2023 |
| KEE Business Services Ltd | Information & communication | 2009 |
| Keep Fronting Ltd | Information & communication | 2010 |
| KEG Properties Ltd | Real estate | 2020 |
| Keith Mccoy Associates Limited | Financial services | 2006 |
| Keith's Supermarket Limited | Extraterritorial | 2018 |
| Kelly & O'Shea Limited | Hospitality | 2015 |
| Kelly and Company (MCR) Limited | Real estate | 2021 |
| Kelly Green Living Limited | Manufacturing | 2015 |
| KEN Brogden Ltd | Manufacturing | 2006 |
| Kenak Management Limited | Professional & scientific | 2013 |
| Kenbury Investments Limited | Real estate | 2016 |
| Kenmac Associates Limited | Professional & scientific | 2005 |
| Kennels Green Management Company Limited | Households | 2007 |
| Kenny Automotive Limited | Professional & scientific | 2019 |
| Kensington Maintenance Logistics Ltd | Hospitality | 2010 |
| Kensington Repairs & Logistics Limited | Manufacturing | 2010 |
| Kentstwins Ltd | Wholesale & retail | 2019 |
| Kentview Finance Ltd | Professional & scientific | 2023 |
| Kera Construction Limited | Extraterritorial | 2021 |
| Kerfoot Holdings Ltd | Real estate | 2020 |
| Kershaw Ventures Ltd | Real estate | 2019 |
| Kevin Bocquet Media Ltd | Administrative & support | 2006 |
| Kevin Feddy Media Ltd | Administrative & support | 2013 |
| Kevin Robert Bannan Ltd | Extraterritorial | 2025 |
| Key Homes Properties Ltd | Real estate | 2020 |
| Key Stop Limited | Real estate | 2026 |
| Keyconstruct Limited | Construction | 2023 |
| Keyra Ltd | Wholesale & retail | 2021 |
| Keys to Education Limited | Education | 2025 |
| Keystone Advisory Partners Limited | Information & communication | 2026 |
| Keystone Projects (Hawkshaw) Ltd | Construction | 2018 |
| Keystone Projects (Holdings) Ltd | Financial services | 2018 |
| Keystone Projects (Lancashire) Ltd | Extraterritorial | 2018 |
| KFK Auto Parts Ltd | Wholesale & retail | 2025 |
| KFK Autos Ltd | Wholesale & retail | 2022 |
| KG Courier Services Ltd | Transport & logistics | 2025 |
| KG Luxury Ltd | Manufacturing | 2025 |
| Kgna Limited | Hospitality | 2020 |
| Kgpa Limited | Arts & recreation | 2014 |
| Khalida's Place Ltd | Real estate | 2017 |
| Khany Limited | Health & social care | 2014 |
| Khan’S Quick Kitchen Limited | Hospitality | 2025 |
| Khaosan Investments Ltd | Real estate | 2021 |