| Jorka Limited | Other services | 2023 |
| Jortech Ltd | Professional & scientific | 2022 |
| Josa Capital Limited | Financial services | 2026 |
| Jovolution Limited | Professional & scientific | 2023 |
| Jowett Enterprises Limited | Information & communication | 2009 |
| Jpre Ltd | Real estate | 2024 |
| JR Pearce Ltd | Administrative & support | 2025 |
| Jrmr Ltd | Administrative & support | 2026 |
| Jsap Building Maintenance Ltd | Construction | 2011 |
| JSB Private Healthcare Limited | Financial services | 2015 |
| JSJ Professional Tiling Service Ltd | Construction | 2018 |
| JSY Design Ltd | Professional & scientific | 2012 |
| JT Elite Tiling Co. Ltd | Construction | 2026 |
| JT Travel Services Ltd | Administrative & support | 2023 |
| Juga Limited | Other services | 2023 |
| Jugnoo & Brothers Limited | Wholesale & retail | 2025 |
| Julia Southward Property Ltd | Real estate | 2022 |
| Julian Adams Limited | Professional & scientific | 2000 |
| Julian Davis Engineering Ltd | Construction | 2017 |
| Jumbo Takeaway Ltd | Hospitality | 2024 |
| Junction Architects Limited | Professional & scientific | 2017 |
| June Rose House (Residents) Association Ltd | Real estate | 1997 |
| Juneja Telecom Ltd | Other services | 2018 |
| Juniper LDN Limited | Wholesale & retail | 2022 |
| Junnell Homes Limited | Construction | 2010 |
| Juno’S Studio Ltd | Public administration | 2026 |
| Just ADD Drums Ltd | Manufacturing | 2024 |
| Just ADD VR Ltd | Information & communication | 2018 |
| Just Electricians Ltd | Construction | 2025 |
| Just Law Legal Services Limited | Professional & scientific | 2025 |
| Just Legal Limited | Manufacturing | 2002 |
| Just Products Limited | Wholesale & retail | 2020 |
| Just Value IT Limited | Administrative & support | 2013 |
| JVP Investment Properties Ltd | Real estate | 2025 |
| JW Plant Repairs and Sales Ltd | Manufacturing | 2019 |
| JW Properties Management Ltd | Real estate | 2023 |
| JWD Sussex Limited | Professional & scientific | 2013 |
| JWE Limited | Administrative & support | 2008 |
| K Brogan Ltd | Construction | 2010 |
| K M V Finnance UK Ltd | Administrative & support | 2000 |
| K R S Plumbing and Heating Ltd. | Wholesale & retail | 2004 |
| K S Luxford Ltd | Manufacturing | 2002 |
| K-Lite Europe Ltd | Wholesale & retail | 2015 |
| K.A.R.S Sussex Limited | Wholesale & retail | 2005 |
| KA Projects Ltd | Professional & scientific | 2021 |
| Kaabros Limited | Wholesale & retail | 2004 |
| Kaabros Properties Ltd | Real estate | 2025 |
| Kaabros Rentals LLP | | 2023 |
| Kaago Holdings Limited | Professional & scientific | 2019 |
| Kaago Properties Limited | Real estate | 2022 |
| Kableyco Ltd. | Mining & quarrying | 2007 |
| Kadamco Ltd | Information & communication | 2022 |
| Kaddshop LLP | | 2025 |
| Kaeru Consulting Limited | Administrative & support | 2011 |
| Kaerus Recruitment Ltd | Professional & scientific | 2024 |
| Kagulex Consulting Ltd | Professional & scientific | 2000 |
| Kaianite Limited | Extraterritorial | 2025 |
| Kaicase Limited | Extraterritorial | 2025 |
| Kaizen Clouds Ltd | Information & communication | 2009 |
| Kalaranga Ltd | Wholesale & retail | 2020 |
| Kalleyedo Limited | Information & communication | 2020 |
| Kamai Limited | Information & communication | 2014 |
| Kamara Healthcare Limited | Health & social care | 2013 |
| Kamima Ltd | Professional & scientific | 2021 |
| Kapff Medical Limited | Health & social care | 2009 |
| Kapow Designs and Merchandise Ltd | Wholesale & retail | 2023 |
| Kapow Events Ltd | Arts & recreation | 2025 |
| Kapow Wrestling Ltd | Arts & recreation | 2022 |
| Kardia Coaching & Mentoring Ltd | Administrative & support | 2020 |
| Karenza Court Management Company Limited | Households | 1978 |
| Karishma's Heritage Ltd | Wholesale & retail | 2025 |
| Kate Bates Limited | Information & communication | 2020 |
| Kate Coote Limited | Professional & scientific | 2017 |
| Kate Dean Consulting Ltd | Real estate | 2014 |
| Kate Pincott Ltd | Information & communication | 2020 |
| Katie Parker Ltd | Financial services | 2024 |
| Kaur Relocations Ltd | Real estate | 2025 |
| Kavalan Conservation Ltd | Agriculture & fishing | 2021 |
| Kayel Brewery Supplies Limited | Manufacturing | 1966 |
| Kaykat Consulting Limited | Professional & scientific | 2022 |
| KB Design and Promotion Limited | Wholesale & retail | 1988 |
| KCB Investments LLP | | 2008 |
| Keenes Events Limited | Other services | 2018 |
| Keeping Blue Ltd | Professional & scientific | 2010 |
| Kegra Ltd. | Health & social care | 2015 |
| Keiba Solutions Limited | Administrative & support | 2006 |
| Keiba Technologies Limited | Information & communication | 2007 |
| Keith George Ltd | Construction | 2013 |
| Kelag Analytics Ltd | Information & communication | 2025 |
| Kelly's Coffee Ltd | Hospitality | 2021 |
| Kelsey Limited | Professional & scientific | 2019 |
| Kempshott Mews Management Company Limited | Households | 2001 |
| Kenko Yasai Limited | Wholesale & retail | 2025 |
| Kentwyns Estate Management Company Limited | Households | 2005 |
| Kentwyns Freeholders Company Limited | Other services | 2008 |
| Kernow Holiday Cottages LLP | | 2022 |
| Kershaw Foulds Limited | Wholesale & retail | 2026 |
| Kerves Lane Property Management Company Limited | Households | 1997 |
| Kevin Morley Marketing Limited | Professional & scientific | 1992 |
| Kevin O’Keeffe & Co Limited | Extraterritorial | 2011 |