| Keyj Limited | Households | 2016 |
| Keylend Enterprises Limited | Households | 1994 |
| Keylynx House Supported Living Ltd | Health & social care | 2019 |
| Keyrise Property Services Ltd | Real estate | 2025 |
| Keyscouts Ltd | Real estate | 2024 |
| Keyside RTM Company Limited | Households | 2005 |
| Keystone (Banstead) Management Company Limited | Households | 2023 |
| Keystone Accountancy Limited | Professional & scientific | 2020 |
| Keystone Managment and Consultancy Ltd | Education | 2025 |
| Keysurance Limited | Extraterritorial | 2013 |
| Keyte & Co Ltd | Professional & scientific | 2003 |
| KEYZ2SUCCESS Limited | Education | 2006 |
| Kezban Media and Publishing Limited | Information & communication | 2013 |
| KFA Properties UK Limited | Real estate | 2025 |
| KFHEATING9 Services Limited | Construction | 2025 |
| KFS Wholesale Ltd | Hospitality | 2025 |
| KG Global Ltd | Real estate | 2024 |
| KG Group (South London) Limited | Real estate | 2021 |
| Kgdk Limited | Information & communication | 2021 |
| KGM Beauty Ltd. | Other services | 2014 |
| KGM Ltd | Construction | 2016 |
| KGN Properties GRP Limited | Real estate | 2021 |
| KGR Constructions Limited | Construction | 2025 |
| Khaigreen Limited | Wholesale & retail | 2024 |
| Khalifah Capital Partners Limited | Professional & scientific | 2025 |
| Khalm Property Maintenance Ltd | Construction | 2024 |
| Khalsa & Sons Ltd | Wholesale & retail | 2019 |
| Kham Basalat UK Ltd | Wholesale & retail | 2026 |
| Khan Building Services Ltd | Construction | 2024 |
| Khan Distributers Limited | Wholesale & retail | 2025 |
| Khan Fast Foods Limited | Hospitality | 2025 |
| Khan Finance Group Limited | Construction | 2023 |
| Khan Investment Group (MK) Limited | Financial services | 2025 |
| Khan Investment Group (SK) Limited | Financial services | 2025 |
| Khan Investment Group Limited | Real estate | 2025 |
| Khan London Services Ltd | Construction | 2020 |
| Khan Property Group Limited | Real estate | 2024 |
| Khan Vape Ltd | Wholesale & retail | 2025 |
| Khanagi London Limited | Hospitality | 2025 |
| Khans Enterprises Ltd | Wholesale & retail | 2018 |
| Khawaja Nazar Properties Ltd | Real estate | 2023 |
| Khaya Oasis LLP | | 2025 |
| Khayelihle Limited | Health & social care | 2010 |
| Khd&Co Ltd | Transport & logistics | 2025 |
| Kheem Concept Limited | Construction | 2025 |
| Khera Investment Solutions Ltd | Financial services | 2020 |
| Khidauna Ltd | Wholesale & retail | 2018 |
| Khiz Accounting Ltd | Professional & scientific | 2019 |
| Khrusalis Limited | Information & communication | 2016 |
| Khye Fire Ltd | Public administration | 2020 |
| Ki-Force Limited | Other services | 2015 |
| Kiba Kitchen & Bathroom Designs Limited | Construction | 2012 |
| Kiboko Consulting Limited | Professional & scientific | 2011 |
| Kick Action Academy CIC | Education | 2023 |
| Kickstart Connections Ltd | Administrative & support | 2025 |
| Kiddco Ltd | Health & social care | 2019 |
| Kiddiplay Ltd | Other services | 2023 |
| Kiddnova Limited | Real estate | 2021 |
| Kidnam Limited | Health & social care | 2026 |
| Kids Paradise Preschool Ltd | Education | 2016 |
| Kids-Joy Nursery Ltd | Education | 2025 |
| Kidseeks Limited | Wholesale & retail | 2025 |
| Kidzsmile Ltd | Arts & recreation | 2026 |
| Kierkeuk Ltd | Information & communication | 2026 |
| Kieryan Care Limited | Households | 2022 |
| Kigno African Food Limited | Hospitality | 2025 |
| Kigno Taste Kitchen Ltd | Hospitality | 2026 |
| Kiki M Consulting Limited | Professional & scientific | 2020 |
| Kiko BG Ltd | Administrative & support | 2020 |
| Killer Communications Limited | Administrative & support | 2011 |
| KIM MI SA Limited | Other services | 2026 |
| Kimael Ltd | Information & communication | 2018 |
| Kimani Moore Entertainment Limited | Information & communication | 2016 |
| Kimatsu Care Services Limited | Health & social care | 2024 |
| Kimbaston Flat Management Company Limited | Households | 1976 |
| Kimberley Close Management Company Limited | Households | 1987 |
| Kimberley Constructions Limited | Construction | 2021 |
| Kimbolton Residents Management Company Limited | Households | 2006 |
| Kimchi 360 Ltd | Wholesale & retail | 2023 |
| Kimka Collective Ltd | Real estate | 2025 |
| Kindling Finance Limited | Education | 2025 |
| Kindy Ltd | Real estate | 2024 |
| King Edward Court (Cedars) Residents Company Limited | Households | 2005 |
| King Edward Court Management Company Limited | Households | 1992 |
| King of Salem International Ministries | Other services | 2019 |
| Kingatravel Ltd. | Administrative & support | 2009 |
| Kingdom Business Records Limited | Arts & recreation | 2018 |
| Kingdom Design Solution Limited | Professional & scientific | 2025 |
| Kingdom Heritage Christian Fellowship | Other services | 2012 |
| Kingfisher Court (Cambridge) Limited | Households | 2002 |
| Kingfisher Court (Fleet) Management Company Limited | Households | 2004 |
| Kingfisher Place (Shepperton) Management Company Limited | Households | 2007 |
| Kingmaker Global Ltd | Administrative & support | 2017 |
| Kings Court (Bristol) Management Company Limited | Households | 2007 |
| Kings Court (Huddersfield) Property Management Limited | Households | 2002 |
| Kings Flats Flitwick Limited | Households | 1987 |
| Kings Gate (Addlestone) Management Company Limited | Households | 2005 |
| Kings Langley College Limited | Education | 2023 |
| Kings Lodge (Chilwell) Management Company Limited | Households | 2004 |
| Kings Parade Trustees Limited | Extraterritorial | 2025 |