| Julia Silver Tutoring Limited | Education | 2026 |
| Julian Mansfield Associates Limited | Professional & scientific | 2014 |
| Jump Rope Theatre Ltd | Arts & recreation | 2023 |
| Jumpbeck Limited | Transport & logistics | 2024 |
| Jupiter Planning Ltd | Professional & scientific | 2022 |
| Just Arthur Ltd. | Manufacturing | 2020 |
| Just B2B Payments Ltd | Administrative & support | 2024 |
| Just B2B Protection Ltd | Financial services | 2026 |
| Just Care for Everyone Limited | Health & social care | 2025 |
| Just Concrete Services Ltd | Administrative & support | 2016 |
| Just Grab Services Limited | Construction | 2005 |
| Just IT Consultant Ltd | Information & communication | 2017 |
| Just Jersey Limited | Manufacturing | 2002 |
| Just Miniatures Limited | Wholesale & retail | 2003 |
| Just Seek Limited | Education | 2024 |
| Justquants Ltd | Administrative & support | 2023 |
| JVR Resources Limited | Other services | 2014 |
| JW & LW Services Limited | Administrative & support | 2025 |
| JW Physio Clinic Limited | Health & social care | 2022 |
| JWA Consulting Limited | Administrative & support | 2016 |
| JWC Projects Ltd | Construction | 2016 |
| Jwfk Limited | Administrative & support | 2010 |
| Jwkpl Ltd | Financial services | 2015 |
| JWM Services Limited | Administrative & support | 2025 |
| Jwsalonsolutions Ltd | Other services | 2023 |
| Jwsm Services Ltd | Construction | 2024 |
| JYK Limited | Professional & scientific | 2021 |
| JZT Sourcing Limited | Wholesale & retail | 2025 |
| K & H Estates Limited | Financial services | 2023 |
| K & S Contracts Limited | Construction | 2019 |
| K Sivakolunthu Ltd | Health & social care | 2021 |
| K Stuf Ltd | Administrative & support | 2015 |
| K. & R. Manufacturing Limited | Manufacturing | 1994 |
| K. J. Cole Electrical Ltd | Manufacturing | 2012 |
| K. Martin (Sudbury) Holdings Limited | Financial services | 2024 |
| K. Martin Group Limited | Real estate | 2024 |
| K. Martin Holdings Limited | Financial services | 2024 |
| K.M.I Construction Ltd | Construction | 2016 |
| K25 Plumbing Ltd | Construction | 2012 |
| K418 Arts Ltd | Arts & recreation | 2015 |
| K7 Minibus Ltd | Transport & logistics | 2021 |
| Kaboodle Digital Limited | Administrative & support | 2017 |
| Kafkas 36 Ltd | Hospitality | 2026 |
| Kalan Group Ltd | Real estate | 2019 |
| Kalan Homes Limited | Construction | 2020 |
| Kaledemir Ltd | Real estate | 2025 |
| Kalel Developments Ltd | Construction | 2020 |
| Kalph BIO Security Limited | Transport & logistics | 2021 |
| Kamulla LLP | | 2012 |
| Kana Capital Limited | Extraterritorial | 2025 |
| Kanco Bricks Ltd | Real estate | 2020 |
| Kanco Estates Ltd | Real estate | 2023 |
| Kanco States Ltd | Real estate | 2023 |
| Kanta Kanbi Limited | Other services | 2012 |
| Karia Jewellery Ltd | Wholesale & retail | 2020 |
| Karinah Food Hub Limited | Hospitality | 2025 |
| Karlin Investment Ltd | Real estate | 2024 |
| Karlson Consultants Limited | Professional & scientific | 2017 |
| Karly Ltd | Administrative & support | 2021 |
| Karnel Investments Limited | Real estate | 2009 |
| Kartik Assets Limited | Real estate | 2019 |
| Kartik Developments Ltd | Other services | 2018 |
| Kartik Holdings Limited | Real estate | 2018 |
| Kartik Lakshmi Limited | Real estate | 2021 |
| Kartik Portfolio Limited | Real estate | 2019 |
| Kasa Build Consulting Ltd | Professional & scientific | 2020 |
| Kase Care Limited | Health & social care | 2019 |
| Kase Construct Limited | Construction | 2022 |
| Kase Homes Limited | Real estate | 2024 |
| Kasim Local Ltd | Wholesale & retail | 2021 |
| Kate Morley PR Limited | Professional & scientific | 2015 |
| Kate's Homemade Ltd | Wholesale & retail | 2020 |
| KAY Copeland Limited | Professional & scientific | 2025 |
| Kazzy's Desserts Ltd | Hospitality | 2023 |
| KB Workings Limited | Arts & recreation | 2010 |
| KBB Concept Limited | Construction | 2023 |
| Kbfs Specialist Ltd | Administrative & support | 2016 |
| Kc-Ren Limited | Real estate | 2021 |
| KDL Hospitality LLP | | 2025 |
| KEEN2CLEAN Exterior Cleaning Ltd | Administrative & support | 2021 |
| Keenes Property Limited | Real estate | 2021 |
| Keepbuzz Ltd. | Information & communication | 2023 |
| Keepstay Limited | Extraterritorial | 2005 |
| Keith Tucker LLP | | 2014 |
| Kelika Digital Ltd | Information & communication | 2017 |
| Kelleher Murphy Electrical Services Ltd | Construction | 2024 |
| Kelly Associates Limited | Construction | 1990 |
| Kelsworth Limited | Construction | 2008 |
| Kemi ADE 2026 Limited | Real estate | 2025 |
| KEMP43 Investments Ltd | Real estate | 2022 |
| Kempton Court Freehold Ltd | Administrative & support | 2002 |
| Kenbarico Properties Limited | Real estate | 2025 |
| Kendan Cars Limited | Wholesale & retail | 2015 |
| Kenilworth Consulting Ltd | Information & communication | 2010 |
| Kenner Limited | Administrative & support | 2008 |
| Kensington Painters & Decorators Ltd | Construction | 2025 |
| Kesas Properties Ltd | Real estate | 2024 |
| Kevin Brown Limited | Professional & scientific | 2020 |
| Kevin Juniper Ltd | Manufacturing | 2025 |
| Kewthorpe Limited | Real estate | 1963 |