| Keep Calm and Carry on Beverage Company Limited | Manufacturing | 2010 |
| Keep Calm Drinks London Limited | Manufacturing | 2015 |
| Keep IT UP Limited | Construction | 1998 |
| Keeptax Limited | Professional & scientific | 2023 |
| Keeran (London) Limited | Construction | 2015 |
| Keeran Designs Limited | Construction | 2001 |
| Keeran Engineering Limited | Construction | 2010 |
| Keezy Ltd | Wholesale & retail | 2024 |
| Keke Aesthetics Ltd | Other services | 2025 |
| Keke Limited | Hospitality | 2018 |
| Keller Academic Services Limited | Education | 2013 |
| Keller Stones Property Limited | Real estate | 2015 |
| Kelly Care LON Ltd | Administrative & support | 2023 |
| Kelly's Kids Ltd | Health & social care | 2010 |
| Keluar UK Trading Ltd | Wholesale & retail | 2012 |
| KEM Mortgages Ltd | Financial services | 2025 |
| Kemat Consulting Limited | Information & communication | 2021 |
| Kemet Limited | Manufacturing | 2023 |
| Kemma Property Development and Management Ltd | Real estate | 2016 |
| KEN Beauty Ltd | Other services | 2019 |
| Kendake Honey Ltd | Manufacturing | 2020 |
| Kendake Ltd | Manufacturing | 2022 |
| Kendal Support Services Ltd | Transport & logistics | 2015 |
| Kendans Construction Limited | Construction | 2026 |
| Kengill Limited | Construction | 2023 |
| Kenilworth Urban Limited | Other services | 2022 |
| Kennjane Limited | Real estate | 2014 |
| Kensington Estate & Letting Agents Ltd | Real estate | 2023 |
| Kensington Investments (U.K.) Ltd | Real estate | 2017 |
| Kensington Oakwood Realty Ltd | Construction | 2025 |
| Kensington Place Ltd | Real estate | 2022 |
| Kensington Residences Limited | Real estate | 2021 |
| Kensington Rock Projects Ltd | Extraterritorial | 2017 |
| Kensonlinestores Ltd | Wholesale & retail | 2023 |
| Kent Concrete Services Ltd | Construction | 2023 |
| Kent Home UK Ltd | Real estate | 2024 |
| Kent Motors Ltd | Wholesale & retail | 2022 |
| Kentish Homes Accomodations Ltd | Real estate | 2023 |
| Kentish Homes Limited | Real estate | 2013 |
| Kentish Orchard Limited | Information & communication | 2023 |
| Kenton Properties (UK) Limited | Real estate | 2012 |
| Kentucky King Ltd | Hospitality | 2021 |
| Kenwood Investments Ltd | Real estate | 2015 |
| Kenwood Property Group Ltd | Real estate | 2026 |
| Keplor Digital Ltd | Information & communication | 2026 |
| Kera Holdings Limited | Hospitality | 2024 |
| Kera UK Group Limited | Wholesale & retail | 2024 |
| Kerala Limited | Extraterritorial | 2018 |
| Keraniganj Welfare Society UK Ltd | Administrative & support | 2016 |
| Keren Estates Ltd | Real estate | 2022 |
| Kerflo Limited | Information & communication | 1998 |
| Kerria House Ltd | Real estate | 2013 |
| Keru Consulting Limited | Information & communication | 2018 |
| Kesari Events Ltd | Administrative & support | 2025 |
| Kesh Ameen Ltd | Other services | 2018 |
| Keshar Accountancy Limited | Professional & scientific | 2025 |
| Keshav Enterprise Co & Ltd | Wholesale & retail | 2026 |
| Keshav TM Services Limited | Transport & logistics | 2025 |
| Kesi Chauffeur Ltd | Transport & logistics | 2016 |
| Kesi Property (Ilford) Ltd | Real estate | 2023 |
| Kesmada Limited | Information & communication | 2025 |
| Kesmir Ltd | Wholesale & retail | 2025 |
| Kesterling Ltd | Wholesale & retail | 2024 |
| Ketha Hair & Beauty Ltd | Other services | 2025 |
| Ketone Energy Ltd | Extraterritorial | 2012 |
| Kevbel Ltd | Real estate | 2016 |
| Kevin 2014 Ltd | Other services | 2017 |
| Kevin&Dolan Construction Ltd | Construction | 2020 |
| Kevkelnat Healthcare Ltd | Health & social care | 2013 |
| Key 2 Homes Properties Limited | Real estate | 2024 |
| Key Code Automotive Ltd | Wholesale & retail | 2025 |
| Key Empire Ltd | Real estate | 2026 |
| Key Home Mortgages Limited | Financial services | 2024 |
| Key Mortgage and Protection Ltd | Financial services | 2022 |
| Key Pubs Ltd | Hospitality | 2018 |
| Key Tech Limited | Information & communication | 2019 |
| Key to Properties (London) Ltd | Real estate | 2020 |
| Keyani Properties Group Ltd | Real estate | 2025 |
| Keybridge Conveyancing Limited | Administrative & support | 2026 |
| Keynest Trading Ltd | Wholesale & retail | 2026 |
| Keystone & Sons Limited | Construction | 2025 |
| Keystone Data Consulting Ltd | Information & communication | 2026 |
| Keystone Maintenance Solutions Ltd | Construction | 2025 |
| Keystone Property Global Ltd | Real estate | 2023 |
| Keystone Scaffolding Ltd | Construction | 2025 |
| Keystride Estates Limited | Households | 2025 |
| Keystyle Estates Ltd | Construction | 2014 |
| Keytons Group Ltd | Wholesale & retail | 2025 |
| Keywise Properties Limited | Real estate | 1999 |
| Keyz Properties Limited | Real estate | 2022 |
| KF & Co Ltd | Education | 2012 |
| Kffit Ltd | Construction | 2026 |
| Kfservices Ltd | Wholesale & retail | 2025 |
| KG Capital Limited | Wholesale & retail | 2025 |
| KG Care Homes Ltd | Health & social care | 2023 |
| KG Facilities Management Ltd | Real estate | 2023 |
| KG Performance Psychology Ltd | Education | 2022 |
| Kgems Braintree Ltd | Education | 2026 |
| Kgems Islington Ltd | Education | 2014 |
| KGN Software Ltd | Information & communication | 2016 |