| KC Consulting (Essex) Limited | Professional & scientific | 2024 |
| KCG Electronics (Midlands) Ltd | Manufacturing | 2015 |
| KD Business Solutions Limited | Professional & scientific | 2016 |
| Kdcm Limited | Health & social care | 2014 |
| Kddcare Limited | Public administration | 2026 |
| Kdgg Invest Limited | Financial services | 2023 |
| KDM International Limited | Wholesale & retail | 1975 |
| KDM Timber Limited | Administrative & support | 2012 |
| KDM Trustee Limited | Financial services | 2005 |
| KDS Groupe Limited | Financial services | 2021 |
| KDW DN Ltd | Other services | 2014 |
| Kebapizza Ipswich Limited | Hospitality | 2019 |
| Keeble Recruitment Solutions Ltd | Administrative & support | 2023 |
| Keebs Group Ltd | Professional & scientific | 2025 |
| Keeles of Hadleigh Limited | | 1962 |
| Keenan Property Services (Essex) Ltd | Construction | 2023 |
| Keep Business Group Limited | Professional & scientific | 2014 |
| Keep Smyelin Limited | Arts & recreation | 2017 |
| Keepemace Ltd | Manufacturing | 2020 |
| Keerthi EM Advisory Ltd | Financial services | 2026 |
| KEF Audio (UK) Limited | Extraterritorial | 1992 |
| Keiran Manners-Consultancy, Training and Community Centred Desistance Ltd | Professional & scientific | 2018 |
| Keith Brett Services Ltd | Construction | 2025 |
| Keith Curson Ltd | Construction | 2016 |
| Keithoclif Consultancy Ltd | Health & social care | 2022 |
| Kell Connect Ltd | Wholesale & retail | 2025 |
| Kellby Ltd | Other services | 2011 |
| Kelly D'S Hair Salon Ltd. | Other services | 2009 |
| Kelly Swingler Ltd | Professional & scientific | 2021 |
| Kelly-Ro Ltd | Transport & logistics | 2019 |
| Kellys Autos and Car Sales Limited | Wholesale & retail | 2025 |
| Keltik Properties Ltd | Real estate | 2023 |
| Kemball Bungalows Private Road Limited | Extraterritorial | 2025 |
| Kemball Electrical Ltd | Construction | 2020 |
| Kemball-Lecompte Consulting Limited | Professional & scientific | 2025 |
| Kembroke Kennels Limited | Administrative & support | 2010 |
| Kemet Capital Ltd | Wholesale & retail | 2024 |
| Kemetic Property Group Ltd | Real estate | 2025 |
| Kemp Rust Consulting Limited | Professional & scientific | 2001 |
| Kendor Properties Limited | Real estate | 1991 |
| Kennel Sales Limited | Real estate | 2004 |
| Kenny Psychology Ltd | Education | 2024 |
| Kent Blaxill Group Limited | Wholesale & retail | 2014 |
| Kent Blaxill Properties Limited | Real estate | 2014 |
| Kent Blaxill Property Holdings Limited | Real estate | 2022 |
| Kent Blaxill Property Limited | Financial services | 2026 |
| Kent Engineering Services Limited | Real estate | 1994 |
| KENT8 Limited | Transport & logistics | 2025 |
| Kentol Estates Ltd | Real estate | 2021 |
| Kenworth Associates UK Limited | Wholesale & retail | 1998 |
| Kenzeal Productions Ltd | Wholesale & retail | 2025 |
| Kenzo&Kemal Ltd | Transport & logistics | 2025 |
| Keocare Limited | Education | 2010 |
| Kepost Limited | Transport & logistics | 2023 |
| Kerbz Ltd | Construction | 2025 |
| Kerry Construction Ltd | Construction | 2018 |
| Kerry Property Investors Ltd | Real estate | 2019 |
| Kersey Mill Weddings and Events Ltd | Hospitality | 2025 |
| Kersey Pest Control Limited | Other services | 2003 |
| Kerseys Law LLP | | 2016 |
| Kerseys Legal LLP | | 2016 |
| Kerseys Solicitors LLP | | 2016 |
| Kershaw Homes Limited | Real estate | 2020 |
| Kervan Cardinal Ltd | Hospitality | 2025 |
| Kervan Supermarket Ltd | Wholesale & retail | 2024 |
| Kesgrave Allotment and Leisure Gardening Association Ltd | Agriculture & fishing | 2011 |
| Kesgrave Builders Ltd | Construction | 2025 |
| Kesgrave Carpets Limited | Professional & scientific | 1996 |
| Kesgrave Cars Limited | Wholesale & retail | 2000 |
| Kesgrave Covenant Limited(The) | Real estate | 1985 |
| Kesgrave Financial Services Ltd | Financial services | 2002 |
| Kesgrave Kitchen Limited | Hospitality | 2019 |
| Kesgrave Project Limited | Health & social care | 2025 |
| Kesgrave Properties Ltd | Real estate | 2026 |
| Kesley Freight Limited | Transport & logistics | 2023 |
| Kestrel Technical Services Ltd | Professional & scientific | 2024 |
| Keswick Hall Norwich Ltd | Financial services | 2022 |
| Kettle Lane Ltd | Construction | 2023 |
| Kevdest Limited | Other services | 2011 |
| Kevin Matias Buda Ltd | Construction | 2020 |
| Kevin R. Culley Engineering Limited | Manufacturing | 2009 |
| Kevin Rodwell Limited | Construction | 2006 |
| Kevron Consulting UK Ltd | Professional & scientific | 2023 |
| Key Clothing Ltd | Wholesale & retail | 2025 |
| Key Education Services Limited | Administrative & support | 2006 |
| Key Focus Publishers Ltd | Information & communication | 2021 |
| Keybase Builders Limited | | 1988 |
| Keycleaners Ltd | Administrative & support | 2025 |
| Keystone Cargo Dynamics Ltd | Transport & logistics | 2025 |
| Keystone Cars Suffolk Ltd | Wholesale & retail | 2026 |
| Keystone Fire Solutions Ltd | Construction | 2026 |
| Keystone IEA Limited | Real estate | 2009 |
| Keystone IMC Limited | Financial services | 2006 |
| Keystone Personnel Ltd | Administrative & support | 2025 |
| KG UK Transport Ltd | Transport & logistics | 2013 |
| Kggstore Ltd | Wholesale & retail | 2023 |
| KGH Management Company Limited | Administrative & support | 2015 |
| Kglabs Ltd | Information & communication | 2018 |
| KGT Window & Door Installations Limited | Construction | 2026 |
| KH Properties Management Limited | Real estate | 2025 |