| Markville Limited | Education | 2002 |
| Martin Brown Property Limited | Real estate | 2022 |
| Matthew Jack Limited | Wholesale & retail | 2016 |
| MC Industrial Roofing Ltd | Construction | 2026 |
| Mdek Utilities Ltd | Construction | 2019 |
| Method Cladding Limited | Construction | 2017 |
| Michael Nugent Maxillofacial Surgery Limited | Health & social care | 2023 |
| Mikey Mike Logistics Ltd | Transport & logistics | 2026 |
| Moshpit Capital Ltd | Professional & scientific | 2024 |
| MP Site Services (NE) Limited | Manufacturing | 2015 |
| Nebula Accessories Limited | Wholesale & retail | 2025 |
| Neil Beattie Consulting Limited | Professional & scientific | 2023 |
| Nellie's Day Nursery Limited | Education | 2018 |
| Newfield Contracts Ltd | Transport & logistics | 2017 |
| North East Boxing - News & Content Limited | Professional & scientific | 2026 |
| North East Cars & Vans Ltd | Wholesale & retail | 2018 |
| Northern Enforcement Services Limited | Administrative & support | 2006 |
| Northern I.T. Ltd | Information & communication | 2017 |
| Northern Metal Recycling Ltd | Wholesale & retail | 2019 |
| Northern Rowing Services Ltd | Manufacturing | 2020 |
| Northquest Renovations Ltd | Construction | 2023 |
| Nourish Hub NE CIC | Hospitality | 2025 |
| NS Clinic & Academy Ltd | Education | 2025 |
| OG Campers Ltd | Manufacturing | 2024 |
| Optimus Mortgages Ltd | Financial services | 2016 |
| Orderandreceive Ltd | Transport & logistics | 2026 |
| Outside Line Consultancy Ltd | Professional & scientific | 2023 |
| Padel Tonic Limited | Arts & recreation | 2025 |
| Painting With Thread Limited | Arts & recreation | 2012 |
| Panda-Charms-Uk Ltd | Wholesale & retail | 2022 |
| PFM Carpets Limited | Wholesale & retail | 2011 |
| PM Racing Ltd | Wholesale & retail | 2017 |
| Proactive Consulting Ltd | Information & communication | 2024 |
| Proactive Technology Group Ltd | Information & communication | 2024 |
| Profile Wines Limited | Wholesale & retail | 2017 |
| Propeller HAT Investments Ltd | Financial services | 2026 |
| PSV Fleet Maintenance Ltd | Manufacturing | 2022 |
| Puresprout Limited | Administrative & support | 2024 |
| Pw-Swiftdrop Ltd | Transport & logistics | 2025 |
| Quality Surface Coatings (N.E.) Limited | Construction | 2005 |
| R & K Leisure Ltd | Hospitality | 2013 |
| Racebourne Limited | Wholesale & retail | 1984 |
| Raeesa Tandoori Ltd | Hospitality | 2025 |
| Raymond Mole /T/A Red Lion Shildon Ltd | Hospitality | 2023 |
| Rejuve and Enhance Aesthetics Ltd | Other services | 2025 |
| Renov Ltd | Construction | 2024 |
| Richards Water Solutions Limited | Construction | 2011 |
| Ridley Vibes CIC | Health & social care | 2025 |
| Riley Accountancy Limited | Professional & scientific | 2023 |
| RL Dynamics Ltd | Professional & scientific | 2025 |
| Rmbunker Ltd | Hospitality | 2022 |
| Road Lining Services Ltd | Construction | 2024 |
| Roots of Resilience CIC | Health & social care | 2024 |
| S E Landscaping Limited | Administrative & support | 2014 |
| Santinni Durham Ltd | Hospitality | 2025 |
| Santinni Shildon Ltd | Hospitality | 2022 |
| SC Online Ltd | Wholesale & retail | 2018 |
| SC Systems Ltd | Administrative & support | 2015 |
| Scjj Properties (NE) Limited | Real estate | 2023 |
| Serenity Bathing CIC | Health & social care | 2025 |
| SG Groundworks Solutions Limited | Construction | 2013 |
| Shadow Tech U.K. Limited | Manufacturing | 1998 |
| Shahrp Ltd | Professional & scientific | 2003 |
| Sharcon Monumental Ltd | Manufacturing | 2008 |
| Shawarma City NE Ltd | Hospitality | 2020 |
| Sherridon Ltd | Wholesale & retail | 2020 |
| Shildon AFC CIC | Arts & recreation | 2021 |
| Shildon Association Football Club Limited(The) | Arts & recreation | 1909 |
| Shildon China Chef Ltd | Hospitality | 2019 |
| Shildon Engineering Limited | Professional & scientific | 2013 |
| Shildon Fish &Grill Ltd | Hospitality | 2025 |
| Shildon Manufacturing Company | | 1995 |
| Shildon Masonic Hall (Holdings) Limited | Other services | 2026 |
| Shildon Masonic Hall (Trading) Limited | Other services | 2026 |
| Shildon Stores Ltd | Wholesale & retail | 2020 |
| Shildon Thermoplastics Limited | Manufacturing | 1990 |
| Siberian Reef Durham Ltd | Agriculture & fishing | 2025 |
| Simon Richard Machinery Limited | Administrative & support | 2016 |
| Slipstream Asset Management Ltd | Financial services | 2026 |
| Snaales Limited | Wholesale & retail | 2024 |
| SNG (Shildon) Limited | Hospitality | 2025 |
| Solentec Limited | Manufacturing | 2003 |
| Sordida Terra Ltd | Other services | 2017 |
| South West Durham News CIC | Manufacturing | 2005 |
| Spice Street (Shildon) Limited | Hospitality | 2019 |
| SPS Training Ltd | Extraterritorial | 2025 |
| SSS Works Ltd | Manufacturing | 2024 |
| Stack and Store Ltd | Wholesale & retail | 2020 |
| Stagepoint Studio Limited | Education | 2025 |
| Sumi Limited | Wholesale & retail | 2017 |
| SW Durham Solar Ltd | Construction | 2023 |
| Swift Darlington Ltd | Extraterritorial | 2024 |
| Sympla North East Limited | Manufacturing | 2015 |
| Systemfix Ltd | Manufacturing | 2021 |
| T&G Automotive Ltd | Manufacturing | 1981 |
| T. Daykin Maintenance Ltd | Administrative & support | 2020 |
| T.J Mechanical and Electrical Ltd | Construction | 2023 |
| Taylor Hastwell Steeplejack Services Ltd | Construction | 2025 |
| TDM Design Ltd | Construction | 2023 |
| Teesdale Logistics Ltd | Transport & logistics | 2020 |