| Joining Dots Limited | Professional & scientific | 2006 |
| Jointhedots Coaching Limited | Administrative & support | 2022 |
| Jolly Parson Limited | Real estate | 2020 |
| JON Ayres Heating & Plumbing Ltd | Construction | 2015 |
| JON Ellis Hair Limited | Other services | 2025 |
| Jonathan Anns Limited | Health & social care | 2012 |
| Jonathan Investments Ltd | Administrative & support | 2006 |
| Jonathan Lawes Ltd | Arts & recreation | 2020 |
| Jonathan Roberts Consulting Limited | Administrative & support | 2009 |
| Jones Group Property Holdings Ltd | Real estate | 2024 |
| Jonnic Property Ltd | Real estate | 2024 |
| Jonnieray Entertainment Limited | Arts & recreation | 2012 |
| Jonserv Ltd | Real estate | 2025 |
| Jordan Mason and Associates Limited | Real estate | 2013 |
| Josef K Limited | Hospitality | 2017 |
| Joshua Luke's Ltd | Other services | 2018 |
| Joshua Pulling Ltd | Wholesale & retail | 2026 |
| Josie's Interiors Limited | Wholesale & retail | 2017 |
| Josie’S Delights Ltd | Manufacturing | 2025 |
| Josoti Ltd | Real estate | 2025 |
| Josoti Properties Limited | Real estate | 2025 |
| Joy Jump (Barnsley) Management Company Limited | Households | 2006 |
| JP Aspires Limited | Professional & scientific | 2020 |
| JP Pilates Ltd | Arts & recreation | 2026 |
| JP Wellness Ltd | Real estate | 2026 |
| Jpca Limited | Extraterritorial | 1997 |
| Jphm Property Limited | Real estate | 2026 |
| JPI Warehousing (Soton) Limited | Transport & logistics | 2000 |
| JPM Solar Solutions Limited | Construction | 2016 |
| Jpmc Storage Ltd | Real estate | 2020 |
| JRC PVT Ltd | Hospitality | 2026 |
| JRH Mining Consultancy Limited | Professional & scientific | 2012 |
| JRM Plastering Limited | Construction | 2022 |
| JRP Hants Ltd | Real estate | 2026 |
| JRP Wilts Ltd | Real estate | 2026 |
| JRQ Plumbing and Heating Limited | Construction | 2022 |
| JS Building & Developments Ltd | Construction | 2019 |
| JSA Psychotherapy Limited | Health & social care | 2006 |
| Jscar Events Ltd | Professional & scientific | 2024 |
| JSJ Painters Limited | Construction | 2018 |
| JST Contractors Ltd | Construction | 2014 |
| JSW Building Contractors Ltd | Construction | 2018 |
| JT Deluxe Detailing Ltd | Administrative & support | 2026 |
| JT Editorial Services Limited | Information & communication | 2015 |
| Jubilee Close 1962 Limited | Extraterritorial | 2014 |
| Jubilee Close 1968 Limited | Extraterritorial | 2014 |
| Judwill Ltd | Other services | 2020 |
| Juiceee Point Limited | Wholesale & retail | 2023 |
| Juicy Lucy Ltd | Professional & scientific | 2008 |
| Julia Gill Smiles Ltd | Health & social care | 2015 |
| Julian Corkle Limited | Information & communication | 2010 |
| Julian Crawford Limited | Professional & scientific | 2024 |
| Jump-In Limited | Information & communication | 2013 |
| Jungle & MOO Limited | Information & communication | 2016 |
| Jungle Tavern Ltd | Information & communication | 2025 |
| Jungledrums.Biz Limited | Information & communication | 2003 |
| Juniper & Vine (Fordingbridge) Limited | Wholesale & retail | 2021 |
| Juniper Crew Limited | Information & communication | 2021 |
| Juniper House Gifts & Collectables Ltd | Wholesale & retail | 2023 |
| Juntos Solutions Ltd | Information & communication | 2026 |
| Jurassic Joinery Ltd | Construction | 2024 |
| Jurina Limited | Real estate | 2024 |
| Just Car Shops Limited | Wholesale & retail | 2023 |
| Just Jabs Limited | Health & social care | 2015 |
| Just MEG Littlies Ltd | Real estate | 2021 |
| JVS Foundation Limited | Health & social care | 2018 |
| JW Portfolio Ltd | Real estate | 2022 |
| JW Treecare Limited | Construction | 2023 |
| JWH Contractors Limited | Administrative & support | 2018 |
| JWR Vehicle Services Ltd | Wholesale & retail | 2007 |
| K & N Fish and Chips Ltd | Hospitality | 2026 |
| K & R Civils and Plant Limited | Construction | 2018 |
| K D Ronngren Limited | Professional & scientific | 2021 |
| K Hough Contractors Limited | Construction | 2017 |
| K P Imagery Limited | Professional & scientific | 2019 |
| K R Mould & Sons Limited | Construction | 2004 |
| K S Plastering (Salisbury) Limited | Construction | 2008 |
| K&A Olejnik Services Ltd | Administrative & support | 2021 |
| K.K. Flooring Limited | Construction | 2003 |
| Kaberian Property Management Limited | Real estate | 2023 |
| Kaizen PPM Ltd | Professional & scientific | 2016 |
| Kaleshaven Ltd | Administrative & support | 2024 |
| Kalismo Limited | Real estate | 2024 |
| Kamc Consulting Limited | Professional & scientific | 2005 |
| Kappow Ltd | Professional & scientific | 2019 |
| Karborn 4000 Limited | Arts & recreation | 2021 |
| Kareem Services Limited | Administrative & support | 2010 |
| Karl R Snowden Lettings Ltd | Real estate | 2026 |
| Kashgar (UK) Ltd | Professional & scientific | 2019 |
| Kate Meads Associates Limited | Administrative & support | 2012 |
| Katherine JAY Limited | Health & social care | 2019 |
| Kathmandu Kitchen Salisbury Ltd | Hospitality | 2020 |
| Kaya Rhythm & Arts Limited | Arts & recreation | 2010 |
| Kaybee Autos Ltd | Wholesale & retail | 2025 |
| Kayranli Limited | Hospitality | 2018 |
| Kaysha Sinclair Limited | Administrative & support | 2010 |
| KB Tangerines Ltd | Manufacturing | 2021 |
| KBF Commercials Limited | Other services | 2005 |
| KCA Property Group Ltd | Health & social care | 2026 |
| KCE Properties Limited | Real estate | 2017 |