| Janaa Golden Empire Ltd | Wholesale & retail | 2025 |
| Janat Healthcare Ltd | Health & social care | 2025 |
| Janazah Limited | Education | 2019 |
| Jane Weaver Limited | Professional & scientific | 2017 |
| Janelle & Co Limited | Hospitality | 2025 |
| Jangi Transport Limited | Transport & logistics | 2026 |
| Jannati Libaas Limited | Manufacturing | 2014 |
| Jano Technologies Ltd | Information & communication | 2020 |
| Jansa Express Limited | Wholesale & retail | 2016 |
| JAP Transport London Limited | Transport & logistics | 2026 |
| Japhs Limited | Real estate | 2019 |
| Jarnail Van Line Ltd | Administrative & support | 2016 |
| Jaromaxx Ltd | Transport & logistics | 2015 |
| Jasats IT Consulting Ltd | Information & communication | 2023 |
| Jasbir Holdings Limited | Financial services | 2025 |
| Jask Fabrics Limited | Wholesale & retail | 2008 |
| Jaskaran and Ramnik Limited | Manufacturing | 2025 |
| Jasmin Jawanda Ltd | Transport & logistics | 2021 |
| Jason Hyde Plumbing & Heating Ltd | Construction | 2023 |
| Jason Paskin Limited | Extraterritorial | 2024 |
| Jasper Carrott Limited | Information & communication | 1989 |
| Jassey J Limited | Health & social care | 2019 |
| Jaxamo UK Limited | Professional & scientific | 2017 |
| JAY 10 Limited | Wholesale & retail | 2017 |
| JAY and Co Furniture Limited | Manufacturing | 2020 |
| JAY Doubleu Limited | Information & communication | 2020 |
| JAY Electrician Limited | Construction | 2024 |
| JAY News & Booze Ltd | Wholesale & retail | 2019 |
| JAY Ventures Limited | Construction | 2013 |
| Jaydens Cash and Carry Ltd | Wholesale & retail | 2026 |
| Jayia Constructions Limited | Construction | 2015 |
| Jaylay Movers Ltd | Extraterritorial | 2022 |
| Jays Delivery Ltd | Extraterritorial | 2024 |
| JAZ C Electrical Limited | Construction | 2015 |
| JAZ C Properties Limited | Real estate | 2022 |
| JB Brand Assets Limited | Financial services | 2025 |
| JB Motorsport Car Hire Holdings Limited | Financial services | 2023 |
| JB Motorsport Car Hire Limited | Administrative & support | 2023 |
| JB Real Estate (GB Residential) Ltd | Real estate | 2025 |
| JB Repairs Ltd | Administrative & support | 2025 |
| JB Roof Care Services Limited | Construction | 2015 |
| JB Transport Services Ltd | Transport & logistics | 2025 |
| JB2 Properties Ltd | Real estate | 2022 |
| JBA Catering Limited | Hospitality | 2025 |
| JBM Midland Construction Ltd | Construction | 2021 |
| JBR Properties UK Ltd | Real estate | 2017 |
| JBS Ahmed Properties Ltd | Real estate | 2025 |
| JBS Concrete Ltd | Construction | 2021 |
| JBS Retail Ltd | Wholesale & retail | 2025 |
| JC Driveways & Landscapes Ltd | Construction | 2018 |
| JC International Enterprises Limited | Wholesale & retail | 2020 |
| JC Payne Specialist Services Limited | Wholesale & retail | 2014 |
| Jc's Property Ltd | Real estate | 2016 |
| JCA Advisory Limited | Professional & scientific | 2024 |
| JCD Partitioning Limited | Construction | 2003 |
| JCD Roofs Limited | Construction | 2025 |
| JCN Pubs Limited | Hospitality | 2020 |
| JCP Building Services Limited | Construction | 2011 |
| JCT 7 Car Sales Limited | Wholesale & retail | 2023 |
| JCT 7 Transport Limited | Administrative & support | 2025 |
| JD Associates Ltd | Real estate | 2025 |
| JD Care Properties Ltd | Real estate | 2025 |
| JD Management Consultancy Limited | Professional & scientific | 2016 |
| JD Plant & Engineering Ltd | Construction | 2024 |
| JD Services WM Ltd | Administrative & support | 2025 |
| JD Stravon Ltd | Wholesale & retail | 2025 |
| JDB (U.K.) Ltd | Arts & recreation | 2017 |
| JDE Contracts Ltd | Construction | 2022 |
| Jdmb Restaurants Ltd | Hospitality | 2014 |
| JDP Hotels 2 Limited | Hospitality | 2017 |
| JDP Hotels 3 Limited | Hospitality | 2020 |
| JDP Hotels 4 Limited | Hospitality | 2024 |
| JDP Hotels Holdings Ltd | Professional & scientific | 2017 |
| JDP Hotels Ltd | Hospitality | 2014 |
| JDP Plastering Services Limited | Construction | 2005 |
| JDP Ventures Limited | Construction | 2019 |
| JDS Transport/Services Ltd | Transport & logistics | 2019 |
| Jdswa Limited | Health & social care | 2025 |
| JDW Evans & Co Ltd | Wholesale & retail | 2025 |
| JE Contracts Limited | Construction | 2011 |
| JE Global Enterprises Limited | Administrative & support | 2014 |
| JE International Limited | Health & social care | 2025 |
| Jeaa Group Ltd | Construction | 2026 |
| Jeans Caff Ltd | Hospitality | 2026 |
| JED Housing Limited | Real estate | 2026 |
| JED Property Services Limited | Construction | 2001 |
| Jeda Relocation Limited | Real estate | 2021 |
| Jeera Curry House Ltd | Hospitality | 2023 |
| Jeet Properties Solutions Ltd | Real estate | 2020 |
| Jeet Solutions Limited | Professional & scientific | 2014 |
| Jeeves Estates Limited | Financial services | 2003 |
| Jeeves Investments Limited | Hospitality | 2004 |
| Jefferies Chandler Ltd | Financial services | 2020 |
| Jefferson and Hunter Limited | Professional & scientific | 2007 |
| Jemiool Ltd | Wholesale & retail | 2025 |
| Jeneve Limited | Wholesale & retail | 2016 |
| Jenkins Campers and Conversions Limited | Wholesale & retail | 2025 |
| Jenkins Electrical Ltd | Construction | 2017 |
| Jenkins Haulage Ltd | Transport & logistics | 2026 |
| Jennifer Nails Company Limited | Other services | 2026 |