| Kenward Aviation LLP | | 2014 |
| Kenyon Holdings (Yorkshire) Ltd | Financial services | 2024 |
| Kenyon Property Investors Limited | Real estate | 2024 |
| Kenza Home Contemporary Living Ltd | Professional & scientific | 2023 |
| Kepha Business Services Ltd | Information & communication | 2015 |
| Kepla and Co. Ltd | Construction | 2022 |
| KEPLER-22B Lumina Limited | Manufacturing | 2012 |
| Keppelcove Limited | Professional & scientific | 2019 |
| KER Education Ltd | Education | 2017 |
| Keracol Limited | Professional & scientific | 2011 |
| Keraflo Limited | Manufacturing | 1983 |
| Kerb Appeal Landscaping Limited | Administrative & support | 2012 |
| Kerb Guards Limited | Manufacturing | 2018 |
| Kerbasel Limited | Information & communication | 2025 |
| Kerbin Properties Limited | Construction | 2006 |
| Keresforth Analytics and Advisory Limited | Professional & scientific | 2021 |
| Keri Driver Limited | Information & communication | 2015 |
| Keriwall Appliance Ltd | Wholesale & retail | 2025 |
| Kermokas Ltd | Professional & scientific | 2018 |
| Kero Graphics LLP | | 2010 |
| Kerr Fire Protection Limited | Public administration | 2005 |
| Kerridge & West Company Limited | Real estate | 2026 |
| Kerridge Consult Limited | Professional & scientific | 2016 |
| Kerry Hill Management Company Limited | Professional & scientific | 2006 |
| Kerry Plant Hire Limited | Construction | 2021 |
| Kerry Street Development Limited | Real estate | 2023 |
| Kershaw Plastering Ltd | Construction | 2018 |
| Kerv Capital Limited | Financial services | 2021 |
| Kerv OPS Limited | Administrative & support | 2021 |
| KES Developments Limited | | 1984 |
| Keseru Services Ltd | Administrative & support | 2025 |
| Keshar Limited | Hospitality | 2025 |
| Kesma Investments Limited | Real estate | 2019 |
| Kesshav Consulting Limited | Professional & scientific | 2017 |
| Kessle Properties Ltd | Real estate | 2023 |
| Kest Business UK Limited | Other services | 2009 |
| Kest Properties Limited | Real estate | 2023 |
| Kestrel Property Services Limited | Construction | 2002 |
| Kettlewell Property Services Ltd | Households | 2021 |
| Kettley's Funeral Services Limited | Extraterritorial | 2014 |
| Keville & Co. Consulting Ltd | Financial services | 2025 |
| Kevin & Anne Emsley Limited | Real estate | 2011 |
| Kevin Benstead IFA Limited | Financial services | 2015 |
| Kevin Edward Finance Limited | Financial services | 2022 |
| Kevin Edward Leeds Limited | Administrative & support | 2018 |
| Kevin Kelly Windows Holdings Limited | Financial services | 2008 |
| Kevin Kelly Windows Limited | Manufacturing | 1999 |
| Kevin Kuszyk Ltd | Information & communication | 2011 |
| Kevin Pietersen Limited | Administrative & support | 2004 |
| Kevin Stuart Ltd | Construction | 2019 |
| Kevstev Technologies Ltd | Information & communication | 2023 |
| Kevyan Direct Ltd | Transport & logistics | 2022 |
| KEW Facilities Limited | Administrative & support | 2004 |
| KEW Property Finance Ltd | Financial services | 2019 |
| Kewper Property Limited | Real estate | 2019 |
| Kewprop Ltd | Real estate | 2019 |
| Kexby Investments Limited | Professional & scientific | 2014 |
| Key 900 Limited | Real estate | 2021 |
| Key Admin Solutions Limited | Administrative & support | 2025 |
| Key Appointments (UK) Ltd | Administrative & support | 2009 |
| Key Appointments UK (Franchise) Ltd | Administrative & support | 2021 |
| Key Capital Partners (Carried Interest) III LLP | | 2024 |
| Key Capital Partners (Carried Interest) IX LLP | | 2020 |
| Key Capital Partners (Carried Interest) Viii LLP | | 2014 |
| Key Capital Partners (General Partner) III Limited | Financial services | 2024 |
| Key Capital Partners (General Partner) LLP | | 2006 |
| Key Capital Partners (General Partner) Ltd | Financial services | 2006 |
| Key Capital Partners (General Partner) Viii Limited | Financial services | 2014 |
| Key Capital Partners (Investments) III LLP | | 2024 |
| Key Capital Partners (Investments) IX LLP | | 2020 |
| Key Capital Partners (Investments) Viii LLP | | 2014 |
| Key Capital Partners (Nominees) Limited | Financial services | 2007 |
| Key Capital Partners Fund KCP 1-A | | 2007 |
| Key Capital Partners GP IX Limited | Financial services | 2020 |
| Key Capital Partners III (Nominees) Limited | Financial services | 2024 |
| Key Capital Partners IX (Nominees) Limited | Financial services | 2024 |
| Key Capital Partners LLP | | 2006 |
| Key Capital Partners Viii (Nominees) Limited | Financial services | 2024 |
| Key Elevations Ltd | Real estate | 2017 |
| Key Engineering Solutions Limited | Professional & scientific | 2011 |
| Key Forge Automotive Locksmith Ltd | Wholesale & retail | 2026 |
| Key Hold Ltd | Real estate | 2025 |
| Key Management Consultants Ltd | Professional & scientific | 2015 |
| Key Operations Ltd | Hospitality | 2023 |
| Key Pathways Ltd | Education | 2026 |
| Key Quality Associates Ltd | Professional & scientific | 2019 |
| Key Site Services Ltd | Extraterritorial | 2015 |
| Key Step Mortgage Solutions Ltd | Financial services | 2022 |
| Key Storage Limited | Real estate | 2016 |
| Key to Cure Ltd | Health & social care | 2017 |
| Key Waves Properties Ltd | Real estate | 2026 |
| Key West Pest Control (Northern) Limited | Administrative & support | 2013 |
| Keya Connect Limited | Wholesale & retail | 2020 |
| Keyeta Ltd | Real estate | 2024 |
| Keyls Management Limited | Professional & scientific | 2016 |
| Keymodule Limited | Information & communication | 1993 |
| Keynote Kingdom Limited | Arts & recreation | 2024 |
| KEYS2LET Ltd | Real estate | 2019 |
| Keyshi Superstore Ltd | Wholesale & retail | 2025 |
| Keystay Residences Ltd | Real estate | 2026 |