| Laffey and Jackson Limited | | 1985 |
| Laramide Technologies Ltd | Information & communication | 2025 |
| Laura Garner Ltd | Health & social care | 2018 |
| Lazi Leisure Limited | Professional & scientific | 1998 |
| Lazy Loaded Limited | Information & communication | 2019 |
| LBJ Solutions Ltd | Education | 2020 |
| LET ME in N/E Ltd | Households | 2020 |
| Lofthouse and Partners (Holdings) Limited | Professional & scientific | 2005 |
| Logisteed UK Limited | Transport & logistics | 1990 |
| Lord Technical Limited | Manufacturing | 1986 |
| Lowther Funeral Services Ltd | Other services | 2018 |
| M & K (Hebburn) Ltd | Wholesale & retail | 2006 |
| M&T Mechanical Engineering Limited | Professional & scientific | 2025 |
| M.A. & P. Barrett (Laminates) Limited | | 1977 |
| M.H.S. Technical Services Limited | | 1980 |
| MA Developments NE Ltd | Real estate | 2019 |
| Made in Kay's Ltd | Other services | 2017 |
| MAF Invest Holdings Limited | Financial services | 2024 |
| Management Company (Bell Street) Limited | Real estate | 2005 |
| Mark Bailey Solutions NE Ltd | Administrative & support | 2024 |
| Martel Scaffolding Limited | Construction | 2004 |
| Martin Nicholas Smith Limited | Extraterritorial | 2022 |
| Maymask (237) Limited | Real estate | 2020 |
| Maymask (XXX) Limited | Financial services | 2020 |
| Mcnally and Thompson (UK Contracts) Limited | Construction | 1997 |
| Mill DAM Portland Limited | Transport & logistics | 2003 |
| Mindmachine Associates Limited | Wholesale & retail | 1992 |
| Minds @ Ease Ltd | Education | 2020 |
| MK1 Support Services Ltd | Construction | 2006 |
| MV Trading Limited | Wholesale & retail | 2007 |
| NEF International Limited | Wholesale & retail | 1975 |
| Netech IT Solutions Ltd | Information & communication | 2014 |
| Netok Limited | | 1979 |
| Newcastle Eagles Holdings Limited | Financial services | 2022 |
| Newcastle Machinery Company Limited | | 1989 |
| Newton Software Solutions Limited | Information & communication | 2003 |
| Nissan Motor Manufacturing (UK) Limited | Manufacturing | 1984 |
| Noahs ARK Hebburn Ltd | Education | 2019 |
| North Durham Holdings Ltd | Financial services | 2023 |
| North East Industrial Solutions Ltd | Other services | 2017 |
| North East Plant Desk Limited | | 1978 |
| Northern Coasters Ltd | Transport & logistics | 2004 |
| Northern Services (N.E.) Ltd | Construction | 2021 |
| Northumbria Aeronautical Collection Limited | Wholesale & retail | 1985 |
| Nova Stellar Property Management Limited | Real estate | 2003 |
| NT Recruitment Ltd | Administrative & support | 2016 |
| Oakview Properties Limited | Real estate | 1988 |
| Ouseburn Quays Limited | Administrative & support | 2020 |
| Outdoor World Limited | Wholesale & retail | 1983 |
| P Jessop Limited | Construction | 2007 |
| Parker Hampton Food Group Ltd | Wholesale & retail | 2021 |
| Pech Holdings Ltd | Financial services | 2024 |
| Physio Plus Clinic Limited | Other services | 2026 |
| PJ Bouncy Castles Ltd | Arts & recreation | 2019 |
| PKB Auto Refinishing Limited | Wholesale & retail | 2015 |
| Poise Performance Ltd | Arts & recreation | 2019 |
| Portnorth Limited | Real estate | 2005 |
| Pristine Healthcare Solutions Limited | Extraterritorial | 2018 |
| Pumphreys Coffee Limited | Extraterritorial | 1980 |
| Quayside Chippy Limited | Hospitality | 2006 |
| Questgate Construction/Building Solutions Ltd | Construction | 2024 |
| R & J CTN Ltd | Other services | 2007 |
| R Management Limited | Other services | 2016 |
| Race Electrical Services (North East) Limited | Construction | 2007 |
| Rainbow Cosmetics Limited | Wholesale & retail | 2005 |
| Rarenow Limited | Agriculture & fishing | 1988 |
| REF Metals Limited | Wholesale & retail | 2005 |
| Residents of Chantry House Limited | Households | 2018 |
| Resin 2 Render Limited | Construction | 2023 |
| Rimoo UK Ltd | Professional & scientific | 2019 |
| Robsons Foodstore Limited | Wholesale & retail | 2003 |
| Rotational Engineering Limited | Manufacturing | 1998 |
| Rowlands Gill Under Fives | Education | 2008 |
| Rutherfords Angling Limited | Wholesale & retail | 2003 |
| S and S Rodgers Accounting Services Limited | Professional & scientific | 2009 |
| S Lucas Electrical Contractors Limited | Construction | 2003 |
| Scanlans (Sunderland) Limited | Administrative & support | 2007 |
| Scott - Bell Property Ltd | Construction | 2017 |
| SD Controls Ltd | Professional & scientific | 2006 |
| Sea Moon Star Limited | Administrative & support | 2016 |
| Seaton Trust Limited | Real estate | 1938 |
| Select Prime Sites UK Ltd | Hospitality | 2003 |
| Shersan Ltd | Administrative & support | 2022 |
| Shields Snooker Centre Limited | Arts & recreation | 1983 |
| Skoti Ltd | Hospitality | 2017 |
| Skyline Loft Conversions (NE) Limited | Construction | 2007 |
| Slater S/S Fabrications Ltd | Other services | 2017 |
| Sloane Court (Jesmond) Management Co Ltd | Households | 1990 |
| Smartspeed Consulting Limited | Professional & scientific | 2007 |
| Sora Group Limited | Financial services | 2025 |
| Southleigh Residents Association Limited | Households | 1984 |
| Spoors Limited | Wholesale & retail | 2025 |
| Srss Ltd | Financial services | 2006 |
| Ssmt Developments Ltd | Real estate | 2023 |
| ST. Aidans Court Management Company Limited | Households | 1992 |
| Stag Renovations Ltd | Real estate | 2019 |
| Stainsby Education Solutions Limited | Education | 2019 |
| Startfirst Limited | Arts & recreation | 1984 |
| Stelrad Limited | Manufacturing | 1988 |
| Steve Grayson Consultancy Ltd | Professional & scientific | 2019 |