| J Rawlings Limited | Other services | 2013 |
| J Sadiq Properties Ltd | Real estate | 2021 |
| J T Atkinson & Sons Limited | Wholesale & retail | 1971 |
| J W Scott Engineering Ltd | Construction | 2016 |
| J Ward Property Holdings Limited | Real estate | 2025 |
| J Wardingham Rope Access Services Ltd | Manufacturing | 2025 |
| J&Co Cleaning Ltd | Administrative & support | 2023 |
| J&D Facilities,Properties & Consulting Ltd | Wholesale & retail | 2021 |
| J&J Electrical (NE) Ltd | Construction | 2013 |
| J&J Plant (NE) Ltd | Construction | 2001 |
| J&M Cabinets Limited | Manufacturing | 2012 |
| J&M Estates N/E Limited | Professional & scientific | 2025 |
| J&M Property Services (NE) Limited | Real estate | 2026 |
| J&R Assets NE Limited | Real estate | 2024 |
| J&Sblastingspryingservies Ltd | Manufacturing | 2022 |
| J. Greene Limited | Professional & scientific | 2023 |
| J. Moore Consultancy Limited | Construction | 2007 |
| J. Pinder Ltd | Professional & scientific | 2017 |
| J.A.R. Developments Limited | Real estate | 2003 |
| J.C Operations Ltd | Professional & scientific | 2024 |
| J.Finn & Sons Joinery and Building Solutions Ltd | Construction | 2025 |
| J.I.H. Properties Limited | Financial services | 2019 |
| J.K. Construction and Joinery Limited | Construction | 2000 |
| J.L Coatings Ltd | Construction | 2025 |
| J.L.Renovation Ltd | Construction | 2023 |
| J.M. Barnfather Limited | Transport & logistics | 2005 |
| J.M. Hare Services Limited | Transport & logistics | 2009 |
| J.Park Scaffolding Limited | Construction | 2017 |
| J.Pazfab Ltd | Manufacturing | 2025 |
| J.W. Garnham & SON Ltd | Manufacturing | 2025 |
| J3BOX Limited | Administrative & support | 2018 |
| JA Everritt Electrical Ltd | Construction | 2024 |
| JA Taxi's Limited | Transport & logistics | 2025 |
| JAB Mechanical Services Ltd | Professional & scientific | 2025 |
| Jabran Enterprises Limited | Wholesale & retail | 2021 |
| JAC Endeavours Ltd | Construction | 2025 |
| Jaces (NE) Limited | Professional & scientific | 2015 |
| Jack Cooper Holdings Limited | Financial services | 2026 |
| Jack Dean Ltd | Construction | 2017 |
| Jack Donnelly Construction Limited | Construction | 2017 |
| Jack Flynn Construction Ltd | Construction | 2025 |
| Jack Hatfield Sports Club Limited | Hospitality | 2005 |
| Jack's Coaches Ltd | Transport & logistics | 2015 |
| Jackie Group Limited | Wholesale & retail | 2025 |
| Jackson & Partners Limited | Real estate | 2014 |
| Jackson Group Solutions UK Ltd | Administrative & support | 2026 |
| Jacobus Bespoke Furniture Ltd | Manufacturing | 2025 |
| JAD Transport Solutions Ltd | Transport & logistics | 2026 |
| Jadeguard Securities Limited | Extraterritorial | 2011 |
| JAG Mechanical Ltd | Construction | 2024 |
| Jagad Ltd | Hospitality | 2025 |
| Jake Electrical Engineering Contractors Ltd | Construction | 2019 |
| Jakes Mobile Bar Ltd | Wholesale & retail | 2014 |
| Jakloe Teesside Limited | Wholesale & retail | 2016 |
| Jalna Construction Ltd | Manufacturing | 2002 |
| Jalna Investments Limited | Real estate | 2018 |
| Jalna Marine Services Limited | Agriculture & fishing | 2009 |
| Jalna Services Ltd | Real estate | 2005 |
| JAM Signature Hospitality Ltd | Hospitality | 2025 |
| Jamcproperties Ltd | Real estate | 2025 |
| James Clark Construction Limited | Construction | 2017 |
| James Cook Discovery Ltd | Real estate | 2016 |
| James Downing Consultancy Ltd | Professional & scientific | 2018 |
| James Healey Ltd | Construction | 2023 |
| James NDT Inspection Ltd | Professional & scientific | 2024 |
| James Paul Services to Industry Limited | Construction | 1994 |
| James's Place Limited | Health & social care | 2024 |
| Jamie Beattie Technical Services Ltd | Professional & scientific | 2026 |
| Jamie Judo Coaching Ltd | Arts & recreation | 2024 |
| JAN Bezemer & Sons Limited | Energy | 2002 |
| Janakpur Ltd | Wholesale & retail | 2026 |
| Jangus Design Ltd | Professional & scientific | 2025 |
| Jansons Group UK Ltd | Wholesale & retail | 2019 |
| Janyalis Ltd | Wholesale & retail | 2023 |
| JAP Euro North East Limited | Wholesale & retail | 2011 |
| Japadad Ltd | Other services | 2012 |
| Japaflex Ltd | Information & communication | 2024 |
| Japanese Car World Ltd | Wholesale & retail | 2022 |
| Jasko Construction Ltd | Construction | 2005 |
| Jason Scanlon Electrical Contractors Ltd | Construction | 2013 |
| Jassi & Sons NE Ltd | Real estate | 2025 |
| Javi Healthcare Group Ltd | Health & social care | 2025 |
| JAW Lifting Ltd | Construction | 2023 |
| Jayden Kabab Mastery Ltd | Hospitality | 2026 |
| Jayden Lettings Limited | Construction | 2017 |
| Jaye House Ltd | Hospitality | 2024 |
| Jayosa Solutions Ltd | Administrative & support | 2022 |
| Jaytre Civils Ltd | Construction | 2024 |
| Jazzyballoons Ltd | Wholesale & retail | 2014 |
| JB Autos NE Ltd | Wholesale & retail | 2021 |
| JB Development North East Limited | Construction | 2021 |
| JB Process Ltd | Professional & scientific | 2025 |
| Jblyth Wind Limited | Professional & scientific | 2022 |
| JBM Solutions Ltd | Construction | 2025 |
| Jboyd Ltd | Administrative & support | 2017 |
| JBS Services (North East) Ltd | Professional & scientific | 2024 |
| JBT Installations Ltd | Construction | 2016 |
| JC 111 Rope Access Limited | Manufacturing | 2025 |
| JC Chinese Catering Ltd. | Hospitality | 2015 |
| JC Hseq Ltd | Construction | 2018 |