| JLK Inspection Limited | Professional & scientific | 2018 |
| JLM Health and Safty Ltd | Professional & scientific | 2026 |
| JLM Music Limited | Arts & recreation | 2018 |
| JLM Property Group Ltd | Real estate | 2025 |
| JLR Consultants Ltd | Professional & scientific | 2024 |
| JLS Investment Group Limited | Real estate | 2020 |
| JLV Comms Ltd | Information & communication | 2026 |
| JLW Rigging Services Ltd | Construction | 2017 |
| JM & CD Property Ltd | Real estate | 2023 |
| JM Access Inspection Ltd | Construction | 2025 |
| JM Brand Property Ltd | Real estate | 2022 |
| JM Consultation Services Limited | Education | 2025 |
| JM CQV Ltd | Professional & scientific | 2025 |
| JM Retail Enterprises Ltd | Wholesale & retail | 2025 |
| JM Wind Solutions Limited | Professional & scientific | 2014 |
| Jm&S Electrical Ltd | Construction | 2025 |
| Jmac Services Ltd | Extraterritorial | 2015 |
| Jmat Consultants Ltd. | Professional & scientific | 2015 |
| JMC Lifting Services Ltd | Professional & scientific | 2018 |
| JME Access Ltd | Construction | 2025 |
| Jmhannon Ltd | Construction | 2026 |
| JMK Automotive Ltd | Wholesale & retail | 2024 |
| JMK Offshore Ltd | Construction | 2018 |
| Jmoc Healthcare Services Ltd | Administrative & support | 2026 |
| JMT Group (NE) Limited | Construction | 2021 |
| JMW GAS Services Limited | Construction | 2025 |
| JN Rusticus Ltd | Wholesale & retail | 2015 |
| JNG Rigging Ltd | Professional & scientific | 2019 |
| JOA Trades Ltd | Wholesale & retail | 2023 |
| Joanne Manning Ltd | Arts & recreation | 2010 |
| Joanne O'Reilly Semi Permanent Makeup & Aesthetics Ltd | Other services | 2021 |
| Jodansisi Properties Limited | Construction | 2025 |
| JOE Mcnamara Lifting Solutions Ltd | Construction | 2017 |
| JOE Wilson Roofing Ltd | Construction | 2024 |
| Joedt Ltd | Professional & scientific | 2025 |
| John & Paul Construction Ltd | Construction | 2025 |
| John Cleaning and Maintenance Ltd | Administrative & support | 2026 |
| John Collins Property Limited | Real estate | 2005 |
| John Davey Limited | Manufacturing | 1981 |
| John Heagney Consulting Limited | Professional & scientific | 2014 |
| John Livingston & Sons,Limited | Financial services | 1924 |
| John Livingston (Estates) Limited | Real estate | 1972 |
| John Sharp (Middlesbrough) Limited | Construction | 2020 |
| John Shell Builders Ltd | Construction | 2022 |
| John Stockton Limited | Hospitality | 2025 |
| Johnathanpeacock Ltd | Construction | 2026 |
| Johns Housing Ltd | Real estate | 2022 |
| Johnson Construction North East Ltd | Construction | 2023 |
| Johnson Electrical Contractors Ltd | Construction | 2026 |
| Johnson Partners Limited | Transport & logistics | 2003 |
| Johnson's Yard Leasehold Management Company (Guisborough) Limited | Hospitality | 2004 |
| Johnson’S Properties North East Ltd | Real estate | 2025 |
| Joint Care Ltd | Administrative & support | 2018 |
| Jojan Limited | Real estate | 2022 |
| Jolda Oasis Properties Limited | Real estate | 2021 |
| Jollof Avenue Ltd | Hospitality | 2026 |
| Jolly Films Limited | Information & communication | 2016 |
| Jolsha Limited | Hospitality | 2009 |
| Jolsha Marton Limited | Hospitality | 2011 |
| JON R Stephenson Limited | Construction | 2024 |
| Jonathan Gibbons Engineering Ltd | Professional & scientific | 2019 |
| Jones & Muir Projects Ltd | Construction | 2023 |
| Jonmac Civil Engineering Ltd | Construction | 2017 |
| Jonmac Group Ltd | Construction | 2025 |
| Jordan Ferrell Ltd | Professional & scientific | 2026 |
| Jordan Mission | Health & social care | 2010 |
| Josef Balog Logistics Ltd | Transport & logistics | 2025 |
| Josef Homes Limited | Real estate | 2020 |
| Joseph Holdings Ltd | Financial services | 2023 |
| Joseph Tait Limited | Professional & scientific | 2023 |
| Josh Cosmetics Limited | Wholesale & retail | 2022 |
| Josh Jones Marketing Ltd | Information & communication | 2025 |
| Josh Smith Limited | Professional & scientific | 2022 |
| Josh Thompson Ltd | Professional & scientific | 2015 |
| Josh Thompson Properties Limited | Real estate | 2022 |
| Joshua Elliott Carpentry Ltd | Manufacturing | 2021 |
| Jotham Engineering Limited | Professional & scientific | 2023 |
| Jotham Management Limited | Professional & scientific | 2023 |
| Journey & Mate Ltd | Information & communication | 2025 |
| Journeys NE Ltd | Transport & logistics | 2019 |
| Joyguru Ltd | Hospitality | 2023 |
| JP Brosnan Ltd | Professional & scientific | 2016 |
| JP Construction Teesside Limited | Construction | 2026 |
| JP Enterprises (NE) Limited | Hospitality | 2017 |
| JP Roofing Teesside Ltd | Construction | 2026 |
| JP Services (NE) Ltd | Professional & scientific | 2020 |
| JPC Care and Support Limited | Health & social care | 2020 |
| JPC Community Hub C.I.C. | Health & social care | 2025 |
| JPC NE Ltd | Construction | 2020 |
| JPC Specialist Motorsports Limited | Administrative & support | 2023 |
| JPM Construction Consulting Limited | Professional & scientific | 2025 |
| JPM Licensing Ltd | Professional & scientific | 2019 |
| JPP Roadworks Limited | Construction | 2025 |
| Jppc Ltd | Real estate | 2026 |
| JR Access Ltd | Construction | 2018 |
| JR Development NE Ltd | Construction | 2020 |
| JR Developments (Northern) Limited | Professional & scientific | 2015 |
| JR Hire Limited | Other services | 2014 |
| JR Personal Limited | Construction | 2025 |
| Jrcass Ltd | Manufacturing | 2025 |