| Jason Cook Limited | Administrative & support | 2011 |
| JF Retail Ltd | Wholesale & retail | 2023 |
| JJ Loft Conversions Ltd | Construction | 2015 |
| JLG Electrical Services Ltd | Energy | 2018 |
| JMC Joinery & Construction Ltd | Construction | 2015 |
| Jodoexhausts Ltd | Wholesale & retail | 2025 |
| John Reid Cars Ltd | Wholesale & retail | 2013 |
| Jones OIL & GAS Services Ltd | Mining & quarrying | 2012 |
| Jscm Consulting Ltd | Real estate | 2009 |
| Juco Limited | Real estate | 2011 |
| Julie Catering Ltd | Hospitality | 2025 |
| Just Motor Group Limited | Wholesale & retail | 2023 |
| Just Peachy Aesthetics Ltd | Other services | 2019 |
| Just Peachy PMU & Training Ltd | Other services | 2018 |
| Just Property Developments Limited | Real estate | 2024 |
| JW Ecology Ltd | Professional & scientific | 2026 |
| K F Energy Ltd | Professional & scientific | 2024 |
| Karen Pescod Ltd | Health & social care | 2015 |
| Kc&Mc Ltd | Hospitality | 2021 |
| KEG Stop NE Limited | Real estate | 2014 |
| Kirk Gillies Ltd | Professional & scientific | 2026 |
| KJB Renewables Ltd | Professional & scientific | 2018 |
| Kymel Group Limited | Extraterritorial | 2019 |
| Kymel Leisure Limited | Hospitality | 2017 |
| Kymel Limited | Professional & scientific | 2013 |
| Kymel Trading Limited | Hospitality | 2013 |
| Land Seismic Services Ltd | Professional & scientific | 2015 |
| Laplata Investments Limited | Real estate | 2018 |
| Lime Tree Sales Ltd | Hospitality | 2018 |
| LJW Services Limited | Other services | 2019 |
| LK Masonry Ltd | Construction | 2022 |
| Longbank Lettings Ltd | Real estate | 2025 |
| Lord Crewe Limited | Hospitality | 2021 |
| LP Project Services Ltd | Professional & scientific | 2020 |
| LRH Superior Services Limited | Construction | 2026 |
| Lsa-Distribution Ltd | Wholesale & retail | 2024 |
| Luminara Group Limited | Construction | 2025 |
| Luther Communities (Special Projects) Limited | Administrative & support | 2014 |
| M and R Autos (NE) Ltd | Wholesale & retail | 2025 |
| M. Smith (Newcastle) Ltd | Wholesale & retail | 2002 |
| Malan Properties Ltd | Real estate | 2023 |
| Management Accounting Services (NE) Limited | Professional & scientific | 2002 |
| Mandrake Estates Ltd | Real estate | 2004 |
| Mansion House (Management) Limited | Real estate | 1985 |
| Mark Lane CC Limited | Professional & scientific | 2021 |
| Martin Structures Limited | Construction | 2018 |
| Matrix H Ltd | Real estate | 2015 |
| Matrix Hazard Management Limited | Water & waste | 2024 |
| Mattison Corporate Services Ltd | Administrative & support | 2019 |
| Maze Hull Ltd | Real estate | 2013 |
| Maze Rooms Ltd | Real estate | 2025 |
| MBS Studios Ltd | Other services | 2026 |
| Mckee Commissioning and Inspection Services Ltd | Construction | 2010 |
| Mechtrade Limited | Administrative & support | 2021 |
| Mendip (North East) Limited | Real estate | 2003 |
| Metal PIG Films Limited | Information & communication | 2007 |
| Michael Irving Ltd | Construction | 2015 |
| Mirai Limited | Financial services | 2019 |
| Miss Fit Breaks Ltd | Arts & recreation | 2023 |
| Miss Fit Dance & Fitness Ltd | Arts & recreation | 2016 |
| Miss Fit Fitness Apparel Ltd | Wholesale & retail | 2024 |
| Morrow Pharmacy Limited | Wholesale & retail | 2001 |
| Moruzzi LEE Ltd | Real estate | 2015 |
| MTD PUB Co Ltd | Hospitality | 2024 |
| Mullen Property Management Limited | Real estate | 2020 |
| Muththumaary Amman Store Ltd | Wholesale & retail | 2023 |
| MW Ecology Ltd | Other services | 2022 |
| My Body Studio Limited | Arts & recreation | 2019 |
| Natgeo Property Ltd | Real estate | 2019 |
| NE44 Limited | Real estate | 2025 |
| Nerh Ltd | Wholesale & retail | 2019 |
| Netherton Club Limited | Hospitality | 2026 |
| NOD Management Ltd | Real estate | 2016 |
| North East Carbon Management Ltd | Professional & scientific | 2025 |
| North East Fencing Ltd | Construction | 2022 |
| North East Roof Training Group Ltd | Administrative & support | 2009 |
| North East Warehousing Solutions Ltd | Transport & logistics | 2022 |
| Nutshell IT Consultancy Limited | Information & communication | 2015 |
| O&L Sheeran Ltd | Arts & recreation | 2023 |
| O'Brien Property Investments Limited | Real estate | 2016 |
| OB CAP Limited | Real estate | 2019 |
| Obr-G Holdings Limited | Real estate | 2022 |
| Obr-N Holdings Limited | Real estate | 2022 |
| Oeuvre Aesthetics Ltd | Administrative & support | 2021 |
| Offermation Ltd | Arts & recreation | 2011 |
| Offshore Lifting Specialist Ltd | Construction | 2026 |
| Oliver Mason Estates Ltd | Real estate | 2024 |
| Olivia's Cafe Ltd | Hospitality | 2025 |
| ON Point North East Aesthetics Ltd | Health & social care | 2023 |
| One Urban FOX Ltd | Wholesale & retail | 2021 |
| OPTION3 Logic Ltd | Professional & scientific | 2023 |
| Oxygen London Ltd | Manufacturing | 2015 |
| O’Brien Aggregate Holding Limited | Mining & quarrying | 2024 |
| O’Brien Aggregate Tuthill Limited | Mining & quarrying | 2024 |
| O’Brien Architectural Salvage Services Limited | Construction | 2019 |
| P & K Management Ltd | Professional & scientific | 2023 |
| P&K Offshore Services Ltd | Extraterritorial | 2024 |
| Paceline Golf Ltd | Manufacturing | 2026 |
| Palmer's Rigging and Lifting Ltd | Construction | 2025 |
| Palmers Accommodation Ltd | Hospitality | 2026 |