| Jbprint Custom Ltd | Manufacturing | 2026 |
| Jbproduction Limited | Arts & recreation | 2006 |
| JBT Auto Limited | Wholesale & retail | 2022 |
| JDS Life Coaching Limited | Arts & recreation | 2014 |
| Jennie Winhall Consulting Limited | Information & communication | 2014 |
| JH Lloyd Consulting Limited | Professional & scientific | 2025 |
| JIB Crew Ltd | Information & communication | 2025 |
| Jigsaw Lettings Limited | Real estate | 2024 |
| Jigsoft Limited | Information & communication | 2007 |
| JIM Cuthbert Japanese Services Limited | Professional & scientific | 2016 |
| JJ Construction Build Ltd | Construction | 2011 |
| JM Fencing Services Limited | Administrative & support | 2024 |
| Jmgr Carpentry and Construction Ltd | Construction | 2023 |
| JMO Partners Limited | Information & communication | 2024 |
| Joanna Davies Private Travel Limited | Administrative & support | 2006 |
| JOE Group Ltd | Information & communication | 2023 |
| John Almeyda Limited | Health & social care | 2012 |
| John Gibb Plastering Limited | Construction | 2001 |
| John’S Tree Services Ltd | Agriculture & fishing | 2014 |
| Jointstake Limited | Construction | 2001 |
| Jollylightuk Ltd | Construction | 2026 |
| Jonkers Media Ltd | Administrative & support | 2021 |
| JP Raffles Ltd | Wholesale & retail | 2022 |
| JR3DPRINTS Ltd | Manufacturing | 2025 |
| Judy Pascoe Limited | Administrative & support | 2009 |
| Jule Frost Limited | Wholesale & retail | 2026 |
| Jumping Juniors Ltd | Education | 2020 |
| Just Another Gadget Ltd | Professional & scientific | 2020 |
| Just Right Solar Solutions Limited | Construction | 2010 |
| Just Value Doors Ltd | Construction | 2015 |
| JV Tree Services Ltd | Administrative & support | 2023 |
| JW Designer Ltd | Professional & scientific | 2024 |
| K Forde Limited | Construction | 2010 |
| K & M (UK) Limited | Wholesale & retail | 2002 |
| KAB Property Investments Ltd | Real estate | 2022 |
| KAM Consult Ltd | Professional & scientific | 2018 |
| Kandy Dance Company Limited | Manufacturing | 2020 |
| Kathleen Bray Hair Limited | Other services | 2008 |
| Kati Gray Limited | Administrative & support | 2006 |
| KAZ Bar Albion Limited | Hospitality | 2015 |
| Kb-Hse Ltd | Professional & scientific | 2016 |
| Kebabulance Limited | Hospitality | 2025 |
| Kellstone Limited | Households | 2001 |
| KEN Field Photography Limited | Professional & scientific | 2004 |
| Kennedy Bros.(Engineers)Limited | Wholesale & retail | 1961 |
| Kent Kerala Care Limited | Health & social care | 2024 |
| Kentish Hills Natural Spring Water Limited | Extraterritorial | 2005 |
| Kershaw Investments Limited | Construction | 2016 |
| Kestrel Electrics Limited | Extraterritorial | 2003 |
| Keto on the Go UK Ltd | Manufacturing | 2019 |
| Key to Sardinia (Rentals) Ltd | Hospitality | 2010 |
| Key to Sardinia Limited | Real estate | 2008 |
| Keysplan Limited | Administrative & support | 2022 |
| Keystone-Structural-Consultants Limited | Professional & scientific | 2015 |
| Kiltmaker Store Ltd | Wholesale & retail | 2024 |
| Kimble Lettings and Property Management Limited | Households | 2014 |
| Kingfisher Career Coaching Ltd. | Administrative & support | 2015 |
| Kings Commerce Ltd | Wholesale & retail | 2023 |
| Kings Electrical Services Limited | Manufacturing | 2021 |
| Kingsfield Business Park Ltd. | Real estate | 1997 |
| Kinygos Limited | Information & communication | 2011 |
| Kipling Close (Crowborough) Management Limited | Households | 2024 |
| Kiss My Aesthetics Ltd | Other services | 2021 |
| KL Connections Limited | Administrative & support | 2008 |
| Klippit Limited | Extraterritorial | 1986 |
| KMD Commercial Associates Ltd | Administrative & support | 2026 |
| Knightsbridge Realty Limited | Construction | 2015 |
| KO Rigging Ltd | Construction | 2025 |
| Kore Outdoor Europe Limited | Arts & recreation | 2021 |
| KOV TN6 Store Limited | Wholesale & retail | 2024 |
| Ksdb Properties Ltd | Real estate | 2006 |
| Ksha Consulting Limited | Professional & scientific | 2018 |
| Kult Media Ltd | Information & communication | 2020 |
| L J Hopwood Consulting Ltd | Professional & scientific | 2025 |
| LA Ditta UK Limited | Administrative & support | 2021 |
| Lakewood Mortgage Solutions Limited | Financial services | 2021 |
| Land of Dreams Limited | Real estate | 2003 |
| Landmark Design and Construction Ltd | Construction | 2017 |
| Lane Organisation Limited | Professional & scientific | 2014 |
| Lantern Film & Video Ltd | Arts & recreation | 1996 |
| Laura Moore Ltd | Professional & scientific | 2022 |
| Leagues Ahead Ltd | Information & communication | 2026 |
| Leapfrog Digital Business Solutions Ltd | Information & communication | 2019 |
| Leaseclass Limited | Professional & scientific | 1992 |
| Leigh White Limited | Professional & scientific | 2008 |
| Lenco Motor Spares Limited | Wholesale & retail | 2004 |
| LES Puces Ltd | Education | 2014 |
| Letts Inventories Ltd | Households | 2024 |
| Lewes Projects Limited | Construction | 2021 |
| Lews Farm Services Limited | Professional & scientific | 2024 |
| Leylands Enterprises Ltd | Professional & scientific | 2017 |
| LG Office Services Limited | Administrative & support | 2003 |
| Liberty Parks Countrywide Limited | Hospitality | 2016 |
| Lidsey Park Limited | Construction | 2024 |
| Linden Management Company Limited | Households | 2006 |
| Link Technical Recruitment Ltd | Administrative & support | 2022 |
| LIS Chinese Takeaway Ltd | Hospitality | 2022 |
| Listex Limited | Professional & scientific | 2011 |
| Literary Lane Ltd | Wholesale & retail | 2025 |
| Live Long and Prosper Health Limited | Health & social care | 2024 |