| JET Wash Cleaning Limited | Administrative & support | 2015 |
| Jgcleaninggroup Limited | Administrative & support | 2025 |
| JGR Performance Limited | Wholesale & retail | 2017 |
| Jh-Surgical Ltd | Health & social care | 2018 |
| JJN Propertys Limited | Real estate | 2020 |
| JJS Waste Management Ltd | Water & waste | 2018 |
| JKH Construction Ltd | Construction | 2020 |
| JKH Seaside (Eastbourne) Limited | Real estate | 2026 |
| JLC Builders Ltd | Construction | 2013 |
| JLC Group Limited | Professional & scientific | 2016 |
| JLM Consultancy Limited | Professional & scientific | 2023 |
| JM CPD Limited | Hospitality | 2015 |
| JM Radiology Limited | Health & social care | 2006 |
| JMH Properties Limited | Real estate | 2019 |
| Jmmk Events Limited | Financial services | 2024 |
| Jmmk Investments Limited | Real estate | 2024 |
| Jmmk Properties Limited | Real estate | 2024 |
| Jmmk Travel (UK) Limited | Extraterritorial | 2023 |
| Jmmk Travel Holdings Limited | Extraterritorial | 2023 |
| JNP (Sussex) Ltd | Real estate | 2017 |
| Jobs Base Ltd | Professional & scientific | 2012 |
| Johnsons Jets Ltd | Administrative & support | 2025 |
| Joint CUT Carpentry & Construction Limited | Manufacturing | 2023 |
| JOL (Guildford) Limited | Other services | 2021 |
| JOL (Wimbledon) Limited | Other services | 2021 |
| JOL Kngston Ltd | Other services | 2025 |
| Jolie Brise (Cornwall) Limited | Other services | 2022 |
| Josh Izzard Tree Surgery Ltd | Administrative & support | 2025 |
| JRD Masonry Limited | Construction | 2019 |
| JRM Mortgage Solutions Ltd | Financial services | 2015 |
| Jscm Holdings Limited | Financial services | 2023 |
| JSD Research & Development Limited | Administrative & support | 1999 |
| JSN Mentoring Ltd | Education | 2021 |
| JSS (South East) Limited | Real estate | 2001 |
| JSS (South East) Property Management Limited | Real estate | 2023 |
| JTR Mechanics Ltd | Wholesale & retail | 2025 |
| Julian Bluck Designs Limited | Professional & scientific | 2003 |
| Julie Barker Consultant Ltd | Professional & scientific | 2019 |
| Jumpfrog Recruitment Ltd | Administrative & support | 2024 |
| Junction 8 Financial Planning Ltd | Financial services | 2020 |
| Juniper Roofing Limited | Construction | 2006 |
| Jupp Carpentry & Construction Limited | Construction | 2023 |
| Just Mortgage Matters Limited | Financial services | 2018 |
| Just Move Consultancy Limited | Health & social care | 2021 |
| Justin Lyward Limited | Wholesale & retail | 2014 |
| JYC Aesthetics Clinic Limited | Other services | 2025 |
| K & J Home and Garden Handyman Services Ltd | Administrative & support | 2023 |
| K & R Lifting Ltd | Construction | 2018 |
| K C Pro Sports Ltd | Manufacturing | 2021 |
| K T Sales Consultancy Ltd | Professional & scientific | 2022 |
| K the Home Fixer Ltd | Construction | 2026 |
| K&J Glow UP Aesthetics Ltd | Other services | 2023 |
| KAI Zammit Filmmaker Limited | Information & communication | 2025 |
| Kairos Surgical Alliance LLP | | 2021 |
| Kallara Investments Limited | Real estate | 2025 |
| Kalnins Taylor Holdings Limited | Financial services | 2024 |
| Kasar Consultancy Limited | Hospitality | 2014 |
| Kate Sanford Properties Limited | Real estate | 2024 |
| Katie Ayyash Limited | Other services | 2018 |
| Katie Tong Consultancy Limited | Professional & scientific | 2017 |
| KB Ents Limited | Information & communication | 2026 |
| KDS Plumbing & Heating Supplies Limited | Wholesale & retail | 2017 |
| Keane Scientific Consulting Limited | Professional & scientific | 2024 |
| Keatley & Barrell Construction Ltd | Construction | 2016 |
| Keder UK Ltd | Wholesale & retail | 2019 |
| Keeley Cricket Limited | Extraterritorial | 2017 |
| Keith Rumary Developments Limited | Real estate | 2019 |
| Keith Rumary Property Co Limited | Real estate | 2019 |
| Kennard Care Services Limited | Other services | 2003 |
| Kensational Ltd | Administrative & support | 2022 |
| Kent & Sussex Urology Ltd | Administrative & support | 2013 |
| Kent Men's Health Ltd | Health & social care | 2025 |
| Kent, Design- Build- Improve Ltd | Construction | 2018 |
| Kenward Windows Limited | Construction | 2015 |
| Kenzo Developments Limited | Extraterritorial | 2021 |
| Kepa Property Ltd | Administrative & support | 2018 |
| Kerry Stubbs Limited | Professional & scientific | 2011 |
| Kestrel Landscaping Ltd | Administrative & support | 2025 |
| Kettleandbelle Ltd | Wholesale & retail | 2025 |
| Kevin O'Neill Ltd | Health & social care | 2015 |
| Key Asset Finance Limited | Financial services | 2024 |
| Key Motor Finance Holdings Limited | Financial services | 2010 |
| Key Motor Limited | Financial services | 2024 |
| Keyborough Services Ltd | Other services | 2024 |
| Keyrise Developments Limited | Real estate | 2025 |
| Khalid Consultants Ltd | Real estate | 2022 |
| Kick OFF Publications Limited | Information & communication | 1999 |
| Kileys Carpets Limited | Wholesale & retail | 2006 |
| Kiln and Home Ltd | Wholesale & retail | 2021 |
| KIM Care Limited | Health & social care | 2021 |
| Kinetic Pulse Ltd | Arts & recreation | 2026 |
| King Cabinet Makers Limited | Construction | 2008 |
| King Smart Repairs Ltd | Wholesale & retail | 2024 |
| Kingston Morehen Limited | Professional & scientific | 2003 |
| Kirkham Young Limited | Administrative & support | 2004 |
| KJW Holdings Ltd | Financial services | 2024 |
| KKS Surgery Limited | Health & social care | 2012 |
| Kljh Services Limited | Households | 2025 |
| KM Services (Katrina) Limited | Other services | 2020 |
| KMF (Kent) Limited | Extraterritorial | 2003 |