| Juniper Trading Limited | Manufacturing | 2003 |
| Jupiter Asia Ltd | Transport & logistics | 2024 |
| Jurca Holdings Limited | Transport & logistics | 2021 |
| Just Flexi Van Ltd | Transport & logistics | 2025 |
| JUST4LEYA Ltd | Wholesale & retail | 2026 |
| Jutex UK Ltd | Hospitality | 2012 |
| JV Plumbing Ltd | Construction | 2026 |
| Jvhomes Construction Limited | Construction | 2019 |
| JW Ceilings Ltd | Construction | 2023 |
| JWA Tech Ltd | Professional & scientific | 2024 |
| Jwma Plumbing & Heating Ltd | Construction | 2022 |
| Jyaa Properties Ltd | Real estate | 2022 |
| K Britten Groundworks Ltd | Construction | 2019 |
| K Dream Dance Ltd | Education | 2025 |
| K Events Co Ltd | Administrative & support | 2026 |
| K J Cars Ltd | Wholesale & retail | 2017 |
| K M Collections Ltd | Transport & logistics | 2011 |
| K MAN House Limited | Hospitality | 2022 |
| K P Taxis Limited | Transport & logistics | 2003 |
| K Popat Properties Ltd | Real estate | 2025 |
| K Pougher Legal Limited | Professional & scientific | 2018 |
| K S H Property Services Limited | Real estate | 2019 |
| K Smith Electrical Services Limited | Construction | 2023 |
| K Srijee Ltd | Wholesale & retail | 2025 |
| K V N S London Ltd | Hospitality | 2025 |
| K Vince Nail Spa Ltd | Other services | 2022 |
| K&M Creative Limited | Manufacturing | 2009 |
| K&S Tech Solutions Ltd | Information & communication | 2025 |
| K.G.T. Logistics (North West) Limited | Transport & logistics | 2005 |
| K.M.W. Carpenters Limited | Construction | 1997 |
| K.T.C. (Edibles) Bidco Limited | Financial services | 2022 |
| K.T.C. (Edibles) Holdco Limited | Financial services | 2022 |
| K.T.C. (Edibles) Limited | Manufacturing | 1979 |
| K.T.C. (Edibles) Propco Limited | Financial services | 2022 |
| K10-420 Ltd | Wholesale & retail | 2014 |
| K9-SOLID Security Services Ltd | Administrative & support | 2025 |
| Kaaf Consultancy Ltd | Professional & scientific | 2018 |
| KAB AVI Ltd | Professional & scientific | 2018 |
| Kaidiya Capital Ltd | Financial services | 2025 |
| Kainos GAS Limited | Construction | 2019 |
| Kaisa Barrytown PUB Company Ltd | Health & social care | 2025 |
| Kajide Limited | Information & communication | 2014 |
| Kale Consult Ltd | Professional & scientific | 2021 |
| Kallistos House Aesthetics Clinic Limited | Health & social care | 2025 |
| Kalyan Transport Limited | Wholesale & retail | 2024 |
| Kamal Kars Ltd | Wholesale & retail | 2024 |
| Kamra Enterprise Ltd | Administrative & support | 2025 |
| Kandyan Dancers Co Ltd | Arts & recreation | 2022 |
| Kango Enterprise Ltd | Real estate | 2018 |
| Kans Healthcare Ltd | Health & social care | 2026 |
| Karachiites Food Ltd | Hospitality | 2023 |
| Karma Trans Ltd | Transport & logistics | 2025 |
| Karolina Boutique Always Trendy Ltd | Wholesale & retail | 2021 |
| Kasa E-Sports Ltd | Arts & recreation | 2024 |
| KAST92 Integrity Group (KIG) Limited | Real estate | 2020 |
| Kaus Electrical Ltd | Construction | 2024 |
| Kaxton Financial Services Ltd | Professional & scientific | 2021 |
| Kays Accountancy Services Ltd | Professional & scientific | 2011 |
| KB Automation Ltd | Wholesale & retail | 2021 |
| KC Chatter & Cheers Limited | Hospitality | 2025 |
| KCS Couriers Ltd | Transport & logistics | 2022 |
| KCX Ltd | Administrative & support | 2025 |
| KD Custom Consultancy Ltd | Information & communication | 2021 |
| Kdsr Property Investments Ltd | Real estate | 2020 |
| KEB (UK) Limited | Wholesale & retail | 1988 |
| Kebab Empire Ltd | Extraterritorial | 2019 |
| Kecec Ltd | Transport & logistics | 2019 |
| Keedan Commercials Limited | Wholesale & retail | 2021 |
| Keep IT Sweeties Limited | Wholesale & retail | 2022 |
| Keith Carr (Farmers) Limited | Agriculture & fishing | 1959 |
| Keith Nelson & Company Limited | Manufacturing | 2022 |
| Keith Roche Roofing Consultancy Ltd | Construction | 2023 |
| Keldior Ltd | Real estate | 2025 |
| Kelhay Construction Ltd | Construction | 2023 |
| Kellco Ltd | Information & communication | 2022 |
| Kelmar Services Limited | Professional & scientific | 2017 |
| Kennetts Auto Solutions Limited | Wholesale & retail | 2022 |
| Kenny B Transport Ltd | Transport & logistics | 2026 |
| Keri Trucks Ltd | Transport & logistics | 2015 |
| Keriscorp Ltd | Wholesale & retail | 2026 |
| Kerry's Kleaning Ltd | Administrative & support | 2024 |
| Kettering Aquatics Ltd | Wholesale & retail | 2013 |
| Kettering Autos Limited | Wholesale & retail | 2024 |
| Kettering Bearings Limited | Manufacturing | 2010 |
| Kettering Brickwork Limited | Construction | 2008 |
| Kettering Dental Clinic Limited | Health & social care | 2018 |
| Kettering Food Ltd | Hospitality | 2025 |
| Kettering Plastering Limited | Construction | 2009 |
| Kettering Self Storage Centre Ltd | Extraterritorial | 2015 |
| Kettering Selfstore Limited | Real estate | 2016 |
| Kettering Textiles Limited | Water & waste | 1991 |
| Kevin’S Romanian Kitchen Ltd | Hospitality | 2026 |
| Key Figures & Co Limited | Transport & logistics | 2016 |
| Key Solutions Services Ltd | Hospitality | 2021 |
| KF & LF Accommodation Ltd | Hospitality | 2022 |
| KF & LF Property Limited | Real estate | 2015 |
| KF Roofing Services Limited | Construction | 2023 |
| KFM Consultants Limited | Professional & scientific | 2023 |
| KFO Health & Leadership Consulting Ltd | Health & social care | 2025 |
| KG Whittet & Sons Ltd | Real estate | 2018 |