| Keyhole Services Master Locksmiths Limited | Wholesale & retail | 1999 |
| Keyhole Visuals Limited | Professional & scientific | 2014 |
| Keymore Properties Ltd | Real estate | 2023 |
| Keynet Response Limited | Administrative & support | 2021 |
| Keypoint Training Ltd | Education | 2017 |
| Keys 123 Limited | Wholesale & retail | 2024 |
| Keys Industries Ltd | Wholesale & retail | 2020 |
| Keysford Limited | Professional & scientific | 2018 |
| Keystone Bidco Limited | Professional & scientific | 2014 |
| Keystone Financing PLC | Professional & scientific | 2014 |
| Keystone Midco Limited | Professional & scientific | 2014 |
| Keystone Network Solutions Limited | Construction | 2024 |
| Keystone Topco Limited | Professional & scientific | 2014 |
| Keywi Ltd | Wholesale & retail | 2019 |
| Kezzy Burger Ltd | Hospitality | 2022 |
| KG Hudson Properties Ltd | Real estate | 2025 |
| KG Sparks Limited | Construction | 2025 |
| KGP (SHC) Limited | Construction | 2011 |
| KH Plant Training Ltd | Construction | 2015 |
| KH Plumbing & Heating Services Ltd | Construction | 2023 |
| KH Windows Limited | Construction | 2025 |
| Khairy Stores Limited | Wholesale & retail | 2025 |
| Khalid Properties Ltd | Real estate | 2018 |
| Khalid Sherzad Limited | Wholesale & retail | 2025 |
| Khalit Services Limited | Other services | 2026 |
| Khan Food (North) Ltd | Hospitality | 2025 |
| Khan Mobile Shop Limited | Wholesale & retail | 2020 |
| Khan's Cabs Ltd | Transport & logistics | 2022 |
| Khas Management Limited | Construction | 2025 |
| KHB Property Limited | Real estate | 2025 |
| KHM Electrical Services Ltd | Construction | 2025 |
| Khyber Insaf Batan International Co. Ltd | Construction | 2024 |
| Khyrova Ltd | Manufacturing | 2026 |
| KIA Domestic Cleaning Limited | Administrative & support | 2025 |
| Kian's Developments Limited | Real estate | 2015 |
| Kians Meat Supplies Limited | Wholesale & retail | 2019 |
| Kick MPT Ltd | Construction | 2025 |
| Kicks of the Day Ltd | Wholesale & retail | 2021 |
| Kickstart Network Ltd | Professional & scientific | 2022 |
| Kickthebookies Ltd | Professional & scientific | 2025 |
| Kiddal Acquisitions Ltd | Construction | 2022 |
| Kids Little Kingdom Ltd | Health & social care | 2024 |
| Kidz Hub Ltd | Hospitality | 2019 |
| Kidz Playworld Ltd | Other services | 2010 |
| Kielce Trans Ltd | Transport & logistics | 2019 |
| Kierjord Developments Ltd | Households | 2020 |
| Kierson Contemporary Windows Ltd | Construction | 2023 |
| Kierson Yorkshire Ltd | Construction | 2023 |
| Kijs Properties Limited | Real estate | 2023 |
| Kike Giwa Ltd | Information & communication | 2022 |
| Kilbuck Lane Flexi Limited | Energy | 2017 |
| Kilethi Ltd | Real estate | 2025 |
| Kilic Estate Limited | Real estate | 2024 |
| Killer Deal Ltd | Real estate | 2024 |
| Kiln Court Limited | Construction | 2019 |
| Kilrane Beer Co Ltd | Hospitality | 2022 |
| KIM & JOE Co Limited | Construction | 2021 |
| Kimcoh Property Management and Lettings Limited | Real estate | 1999 |
| Kimmergy's Travel Ltd | Administrative & support | 2025 |
| Kinaird Castle Ltd | Construction | 2020 |
| Kinch Aviation Support Ltd | Manufacturing | 2015 |
| Kind & Luxe Soap Company Limited | Manufacturing | 2021 |
| Kinder Vending Ltd | Wholesale & retail | 2016 |
| Kindle Way Limited | Health & social care | 2026 |
| Kindmarket Limited | Manufacturing | 1992 |
| Kinergy Media Ltd | Professional & scientific | 2025 |
| King Fish Limited | Hospitality | 2023 |
| Kingasia Foods Limited | Manufacturing | 1991 |
| Kingdom of MR. T Barbershop Ltd | Other services | 2025 |
| Kingfish 2 Limited | Hospitality | 2025 |
| Kingsway Co (Properties) Ltd | Real estate | 2019 |
| Kingsway Consulting Ltd | Real estate | 1993 |
| Kingswood Restoration Limited | Construction | 2025 |
| Kinkajou IT Limited | Information & communication | 2011 |
| Kinnat Limited | Health & social care | 2025 |
| Kins Barber Shop Limited | Other services | 2025 |
| Kinster Global Ltd | Administrative & support | 2022 |
| Kinx Lingerie Ltd | Manufacturing | 2023 |
| Kirby Lane Limited | Real estate | 2019 |
| Kirdarb Limited | Wholesale & retail | 2024 |
| Kirik Logistics Limited | Transport & logistics | 2015 |
| Kirk Sandall Barbers Ltd | Other services | 2026 |
| Kirk Sandall Barbersz Ltd | Other services | 2025 |
| Kirton Couriers Limited | Transport & logistics | 2018 |
| Kiss Kiss Ltd | Manufacturing | 2024 |
| Kita Catering Ltd | Hospitality | 2025 |
| Kitchen Studio (Doncaster) Limited | Professional & scientific | 2016 |
| Kitchens UK Limited | Professional & scientific | 2002 |
| Kitchin Parker Consultancy Ltd | Professional & scientific | 2014 |
| Kitto Productions Ltd | Information & communication | 2019 |
| Kittycatsupplementsco Ltd | Manufacturing | 2026 |
| Kixx Middlesbrough Limited | Arts & recreation | 2019 |
| Kixx Bassetlaw Limited | Administrative & support | 2017 |
| Kixx Bootle Ltd | Education | 2022 |
| Kixx Derby Ltd | Education | 2020 |
| Kixx Doncaster Limited | Education | 2011 |
| Kixx Durham Ltd | Education | 2022 |
| Kixx Franchising Limited | Education | 2021 |
| Kixx Hull Ltd | Education | 2021 |
| Kixx Kirklees Ltd | Education | 2023 |