| Jescovanice Trading Ltd | Wholesale & retail | 2024 |
| Jess Wardell Design Ltd | Professional & scientific | 2024 |
| JET Pro North East Ltd | Administrative & support | 2023 |
| JET Pubs Ltd | Hospitality | 2024 |
| Jetline Cutting Limited | Manufacturing | 2002 |
| JF Engineering and Operations Services Ltd | Professional & scientific | 2023 |
| JF Investments NE Ltd | Real estate | 2022 |
| JF PUB Group Limited | Hospitality | 2017 |
| JF Surveyors Ltd | Real estate | 2017 |
| Jfre Ltd | Real estate | 2020 |
| JGI Construction Ltd | Construction | 2022 |
| JGI Maintenance Ltd | Construction | 2022 |
| JGI Properties Ltd | Real estate | 2021 |
| Jgweldingsuppliesltd Ltd | Construction | 2025 |
| Jgzhjf Ltd | Information & communication | 2022 |
| JH Luxury Properties Ltd | Real estate | 2025 |
| JH Project Control Limited | Professional & scientific | 2018 |
| JHC Properties Ltd | Households | 2020 |
| Jhsc Consultancy Limited | Health & social care | 2017 |
| JHW Fabrications Ltd | Manufacturing | 2024 |
| Jigsaw Warehousing & Distribution Ltd | Transport & logistics | 2020 |
| Jill Alexander Interiors Ltd | Professional & scientific | 2026 |
| Jimmyx Ltd | Construction | 2024 |
| JIR Windows Ltd | Administrative & support | 2026 |
| JJ Technical Solutions Ltd | Construction | 2026 |
| JJ Wind (NE) Ltd | Construction | 2023 |
| JJC Engineering Ltd | Manufacturing | 2006 |
| JJH Energy Solutions Ltd | Construction | 2026 |
| Jjlk Electrical Limited | Extraterritorial | 2015 |
| JJPROPERTIES24 Ltd | Real estate | 2024 |
| JJS Holdco Limited | Financial services | 2026 |
| JK & J Johnson Grounds Maintenance LLP | | 2022 |
| JK and Brother Ltd | Other services | 2023 |
| JK Waste Management Limited | Water & waste | 2025 |
| Jk's Bar Limited | Hospitality | 2015 |
| JKF Driveways Ltd | Construction | 2025 |
| JKK Investments Limited | Real estate | 2026 |
| JKK Limited | Professional & scientific | 2025 |
| JKN Pipework Installation and Fabrication Ltd | Construction | 2025 |
| JL Consultancy 365 Ltd | Other services | 2018 |
| JL Contracts Limited | Construction | 2023 |
| JL Electrical Services NE Ltd | Construction | 2024 |
| JL Norman Consultants Limited | Professional & scientific | 2018 |
| JLA Global Parts Ltd | Wholesale & retail | 2019 |
| JLC Equestrian Ltd | Agriculture & fishing | 2022 |
| JLD Turbines Ltd | Manufacturing | 2024 |
| JLF Rentals Limited | Hospitality | 2016 |
| JLO Darts Limited | Wholesale & retail | 2025 |
| JLS888 Limited | Households | 2025 |
| Jlwhitehouse Limited | Administrative & support | 2022 |
| JM Commercial Management Limited | Professional & scientific | 2020 |
| JM Inspection Services Ltd | Professional & scientific | 2023 |
| JM Mechanical Industry Ltd | Construction | 2025 |
| JM Plant Hire Limited | Administrative & support | 2018 |
| JM Rigging and Lifting Ltd | Construction | 2025 |
| JM Technical Resources Ltd | Professional & scientific | 2013 |
| Jmac Access Ltd | Construction | 2024 |
| Jmac Contracting Services Ltd | Construction | 2023 |
| JMC Renewable Solutions Ltd | Mining & quarrying | 2018 |
| Jmed Limited | Health & social care | 2009 |
| Jmej Engineering Ltd | Professional & scientific | 2025 |
| Jmfs Financial Planning Limited | Financial services | 2019 |
| JMH Travel Solutions Ltd | Administrative & support | 2024 |
| JMJ Accountants Limited | Professional & scientific | 2009 |
| JMJ Site Safety Services Ltd | Professional & scientific | 2025 |
| JML International Medical Healthcare Specialists Limited | Health & social care | 2015 |
| Jmrelations Limited | Financial services | 2019 |
| JMT Mechanical Fitting Limited | Professional & scientific | 2018 |
| JMW (NE) Limited | Construction | 2023 |
| JMW Digital Marketing Ltd | Professional & scientific | 2024 |
| JMW Estates Limited | Real estate | 2024 |
| JNB Solutions NE Ltd | Information & communication | 2025 |
| Joanne Cowie Notary Public Ltd | Professional & scientific | 2018 |
| Joans Shops Ltd | Wholesale & retail | 2021 |
| JOB Deliveries Ltd | Transport & logistics | 2023 |
| JOB Engineering Ltd | Professional & scientific | 2022 |
| JOE Diez Ltd | Construction | 2025 |
| JOE Maphosa Limited | Arts & recreation | 2021 |
| JOE Ropes Ltd | Construction | 2023 |
| Joemek Supplies Ltd | Wholesale & retail | 2021 |
| Joeparkin Ltd | Transport & logistics | 2026 |
| Jogcash Ltd | Professional & scientific | 2022 |
| JOH Group Ltd | Financial services | 2024 |
| John & Co NE Limited | Professional & scientific | 2024 |
| John Blackburn Consultancy Limited | Professional & scientific | 2023 |
| John Byers Ltd | Energy | 2024 |
| John Cook Pipework Services Ltd | Mining & quarrying | 2017 |
| John G Kemp Services Ltd | Construction | 2012 |
| John H Lithgo & SON Ltd | Manufacturing | 2023 |
| John Murray Farming Ltd | Agriculture & fishing | 2020 |
| John Wade (Holdings) Limited | Financial services | 1997 |
| Johnson & Sons Bespoke Construction Services Ltd | Construction | 2018 |
| Johnson Ventures Limited | Hospitality | 2013 |
| Johnson’S E-Commerce Limited | Wholesale & retail | 2025 |
| Joinery of Excellence Ltd | Construction | 2020 |
| Jojos Coffee Ltd | Hospitality | 2025 |
| Jolla & Co Estates Limited | Real estate | 2024 |
| Jollof Central Ltd | Hospitality | 2025 |
| Jomast 1 Limited | Real estate | 2012 |
| Jomast 2 Limited | Real estate | 2012 |