| Jack Peri Peri Ltd | Hospitality | 2026 |
| Jack Stephen Bailey Ltd | Construction | 2024 |
| Jack's of Norton Limited | Real estate | 2020 |
| Jacket Stop Ltd | Hospitality | 2025 |
| Jackofmosttrades Ltd | Construction | 2024 |
| Jacks Bar and Grill Ltd. | Hospitality | 2017 |
| Jacks Recruitment Limited | Administrative & support | 2015 |
| Jackson's Nurseries (U.K.) Ltd. | Agriculture & fishing | 1991 |
| Jacob Hancock Ltd | Transport & logistics | 2025 |
| Jade Garden 2024 Ltd | Hospitality | 2024 |
| Jadun Ltd | Health & social care | 2024 |
| JAF Commercial Limited | Construction | 2025 |
| JAF Property Rentals Ltd | Real estate | 2025 |
| Jaguar IT Solutions Ltd | Information & communication | 2008 |
| Jahan Motors Ltd | Wholesale & retail | 2023 |
| Jahan Practice Ltd. | Health & social care | 2012 |
| JAI Khan Ltd | Health & social care | 2015 |
| JAI Rose Ltd | Hospitality | 2024 |
| Jaime Hibbert Ltd | Arts & recreation | 2013 |
| Jaime Hibbert Projects Ltd | Administrative & support | 2016 |
| Jaiya Properties Limited | Real estate | 2024 |
| JAK Trade Limited | Wholesale & retail | 2022 |
| Jalani Ltd | Wholesale & retail | 2025 |
| Jalhar Beagles Limited | Agriculture & fishing | 2020 |
| Jama Property Deals Ltd | Real estate | 2023 |
| Jamage Road Management Limited | Construction | 2014 |
| James & Co UK Limited | Administrative & support | 2020 |
| James Accountancy Services Ltd | Professional & scientific | 2006 |
| James Broadhurst & Sons Limited | Real estate | 2012 |
| James Brown Holdings Ltd | Financial services | 2024 |
| James Charles 84 Limited | Health & social care | 2022 |
| James Dawson (China) Limited | Professional & scientific | 1937 |
| James Kent Consolidated Limited | Manufacturing | 2009 |
| James R Properties Limited | Real estate | 2018 |
| Jamie Hunter Ltd | Health & social care | 2025 |
| JAN Japan Autos Limited | Wholesale & retail | 2026 |
| Jane Heath Accounting Solutions Limited | Professional & scientific | 2012 |
| Janisha Limited | Hospitality | 2023 |
| Jarb Ltd. | Public administration | 2016 |
| Jaret Limited | Professional & scientific | 2014 |
| Jaroslaw Spedition Ltd | Transport & logistics | 2016 |
| JAS 1 Logistics Ltd | Transport & logistics | 2025 |
| Jascas Enterprises Ltd | Hospitality | 2019 |
| Jason Humphries Consulting Ltd | Information & communication | 2019 |
| Jason K Pennell Ltd | Transport & logistics | 2026 |
| Jasper Property Services Limited | Real estate | 1997 |
| Jathniel Properties Limited | Real estate | 2025 |
| Jato Property Ltd | Real estate | 2024 |
| Javara Limited | Professional & scientific | 2015 |
| Jawad Pharm Ltd | Wholesale & retail | 2024 |
| Jawdah.Co Ltd | Wholesale & retail | 2020 |
| Jawtoll Ltd | Health & social care | 2024 |
| JAY - Jay's (Stoke) Ltd | Hospitality | 2022 |
| JAY C P Limited | Arts & recreation | 2019 |
| JAY Collins Brickwork Limited | Construction | 2019 |
| JAY Jays Travel Ltd. | Transport & logistics | 2003 |
| JAY Laxmi Kitchen Ltd | Hospitality | 2024 |
| JAY Taylor Rental Services Limited | Real estate | 2015 |
| Jayaram Limited | Real estate | 2026 |
| Jayden Motors Ltd | Wholesale & retail | 2015 |
| Jaykay Fastfood Ltd | Hospitality | 2025 |
| Jayley Collection Ltd | Wholesale & retail | 2005 |
| Jayley Ltd | Wholesale & retail | 2008 |
| Jaypee Transport Ltd | Transport & logistics | 2018 |
| Jaytee Enterprises Limited | Real estate | 1996 |
| Jayty Limited | Health & social care | 2024 |
| JB Aston Engineering Limited | Professional & scientific | 2016 |
| JB BID Management Ltd | Professional & scientific | 2026 |
| JB Process Engineering Services Ltd | Manufacturing | 2011 |
| JB Traders Ltd | Wholesale & retail | 2024 |
| JBG Landscaping Limited | Administrative & support | 2017 |
| JBM & SON Properties Limited | Real estate | 2022 |
| JBM Memorials Limited | Other services | 2017 |
| JBS Go Local Ltd | Wholesale & retail | 2022 |
| JBS Nexus Tech Ltd | Information & communication | 2022 |
| JBS Property Development Ltd | Real estate | 2019 |
| Jbstowrs Ltd | Wholesale & retail | 2024 |
| JC Motorhouse Ltd | Wholesale & retail | 2025 |
| JC Prestige Homes Limited | Real estate | 2020 |
| Jcgpsignal Limited | Hospitality | 2025 |
| JCH Marine & Offshore Supplies Ltd | Wholesale & retail | 2009 |
| Jcjr Prop Limited | Real estate | 2021 |
| JCK Fine Foods Ltd | Manufacturing | 2024 |
| JCL Lettings Limited | Real estate | 2022 |
| JCM Engineering Services Limited | Professional & scientific | 2025 |
| Jcmb Holdings Limited | Financial services | 2026 |
| Jcogginsengineering Limited | Construction | 2024 |
| JCR Football Coaching Limited | Arts & recreation | 2022 |
| JCR Group Holdings Ltd | Financial services | 2026 |
| JCS Industrial Services Limited | Manufacturing | 2002 |
| JCW Joinery Ltd | Construction | 2020 |
| JD & Sons (Civils) Ltd | Construction | 2018 |
| JD Financial Reporting & Consulting Limited | Financial services | 2014 |
| JD Monarch Ltd | Transport & logistics | 2023 |
| JD PVT Ltd | Health & social care | 2017 |
| JD Waste LLP | | 2025 |
| JDB Controls Limited | Professional & scientific | 2025 |
| JDG Motors Ltd | Wholesale & retail | 2025 |
| Jdkinney Capital Limited | Real estate | 2023 |
| Jdkinney Holdings Limited | Administrative & support | 2024 |