| Christian Southern Transport and Logistics Ltd | Transport & logistics | 2025 |
| Clarke's Plumbing Limited | Construction | 2020 |
| Classic Refresh Limited | Wholesale & retail | 2024 |
| Clinic C Ltd | Other services | 2025 |
| Close Range Ltd | Manufacturing | 2026 |
| Cloverdale Property Management Limited | Households | 2026 |
| CO22 Limited | Information & communication | 2012 |
| Coach Connections Limited | Administrative & support | 2013 |
| Coast & Castle Stays Ltd | Real estate | 2026 |
| Coastal Lift Supplies Limited | Wholesale & retail | 2014 |
| Coming Home Commercial Limited | Real estate | 2025 |
| Coming Home Limited | Real estate | 2018 |
| Commissioning + Completion Services (North - East) Limited | Professional & scientific | 2016 |
| Concepts Music Ltd | Information & communication | 2019 |
| Connect 55 Ltd | Professional & scientific | 2019 |
| Conroy Property Investments Ltd | Real estate | 2014 |
| Contenthaus Ltd | Professional & scientific | 2026 |
| Continental Energy and Infrastructure Investment Forum Limited | Financial services | 2025 |
| Coopers Freightmaster Ltd | Transport & logistics | 2017 |
| Coopers Tourmaster Travel Limited | Transport & logistics | 1969 |
| Coredream Consultancy Limited | Administrative & support | 2022 |
| Cosy Stays Northumberland Ltd | Real estate | 2023 |
| Courtney Gibbon Property North Ltd | Hospitality | 2021 |
| Creative Play Solutions Limited | Manufacturing | 2025 |
| CSM Properties (North East) Limited | Real estate | 2025 |
| CTL Distributions Ltd | Wholesale & retail | 2026 |
| Custom Model Works Ltd | Manufacturing | 2025 |
| D & R Recycling Brokers Ltd | Extraterritorial | 2021 |
| D Woods Contractors Limited | Construction | 2009 |
| D.E. Developments (Northumberland) Limited | Extraterritorial | 2016 |
| D2PUB Ltd | Hospitality | 2026 |
| Dalisa Fireplaces Limited | Construction | 2018 |
| Data Masterminds Ltd | Information & communication | 2020 |
| Davison Wealth Management Limited | Financial services | 2020 |
| Davy Access Limited | Mining & quarrying | 2008 |
| Debbie Walker Leisure Ltd | Hospitality | 2022 |
| Demon Corporation Ltd | Extraterritorial | 2021 |
| Detailed Cleaning Solutions Ltd | Administrative & support | 2024 |
| Detm Limited | Extraterritorial | 2020 |
| Devin Purvis Business Consulting Ltd | Professional & scientific | 2022 |
| Devolli Estates Ltd | Real estate | 2025 |
| Digital Inclusive Futures Limited | Information & communication | 2025 |
| Dine at Ashianna Ltd | Hospitality | 2025 |
| DIS Properties Limited | Real estate | 2024 |
| Dlcr Transport Ltd | Transport & logistics | 2015 |
| DLG Joint Integrity Support Limited | Manufacturing | 2025 |
| Dmtm Services Limited | Extraterritorial | 2022 |
| Dou-Tech Limited | Manufacturing | 2022 |
| Dpsmechanical Ltd | Professional & scientific | 2026 |
| DR PIT Allotment Association CIC | Agriculture & fishing | 2017 |
| DR Valet Ltd | Administrative & support | 2019 |
| DRM Roofing Contractors Limited | Construction | 2024 |
| Dsjtm Limited | Construction | 2025 |
| Dunbar Billboard Construction Ltd | Wholesale & retail | 2008 |
| EAO Interiors Ltd | Construction | 2025 |
| Ebdawson Ltd | Professional & scientific | 2023 |
| Eddie Mount Construction Ltd | Construction | 2019 |
| Edges of Time Limited | Extraterritorial | 2006 |
| Eight Station Street Limited | Hospitality | 2019 |
| Electri-Cal NE Ltd | Construction | 2026 |
| Elite Property Services NE Ltd | Administrative & support | 2024 |
| Embletons Welding Services Ltd | Manufacturing | 2014 |
| Emmerson Group Ltd | Construction | 2023 |
| Emmerson Investments Ltd | Real estate | 2025 |
| Empire Finishes Ltd | Construction | 2026 |
| Energyze Consulting Limited | Administrative & support | 2023 |
| Energyze Property Ltd | Real estate | 2025 |
| Enriched Consulting Ltd | Professional & scientific | 2016 |
| Established Counsel Limited | Extraterritorial | 2026 |
| Fair Avenue Management Company Limited | Administrative & support | 2015 |
| Falcon FOX Developments Ltd | Construction | 2017 |
| Falon Nameplates Limited | Manufacturing | 1998 |
| FFD Holdings Ltd | Real estate | 2024 |
| Fielding Accountancy Services (Northumberland) Limited | Professional & scientific | 2025 |
| Fieldview Developments Ltd | Extraterritorial | 2005 |
| Fine and Dandi C.I.C. | Information & communication | 2021 |
| Float IT Ltd | Administrative & support | 2013 |
| Food 4 Less & £ Plus Ltd | Wholesale & retail | 2023 |
| G Dawson Engineering Consultants Limited | Professional & scientific | 2019 |
| G H Properties (N.E.) Limited | Real estate | 2005 |
| G M Floor Covering Limited | Construction | 2019 |
| Gadsby & Long LYD Ltd | Hospitality | 2024 |
| Garveys Properties Ltd | Real estate | 2020 |
| Glen Anthony Watches Ltd | Manufacturing | 2021 |
| Glenpark Developments Limited | Real estate | 2020 |
| GM Joinery and Building Ltd | Construction | 2020 |
| GM Property North East Ltd | Real estate | 2024 |
| Grays Cafe Bar Ltd | Hospitality | 2019 |
| Greatest on Earth Ltd | Construction | 2018 |
| Grove Square Supplies Limited | Wholesale & retail | 2023 |
| GTD Project Solutions Limited | Professional & scientific | 2026 |
| GW Dental Equipment Ltd | Health & social care | 2024 |
| H2O Heating Solutions Limited | Construction | 2011 |
| Hadrian Geomatics Ltd | Professional & scientific | 2024 |
| Hapcal Ltd | Information & communication | 2023 |
| Hartford Hall Engineering Services Limited | Professional & scientific | 2015 |
| Hartford Mews Management Company Limited | Households | 2002 |
| Hech Engineering Limited | Manufacturing | 1973 |
| Heddon 62 Limited | Extraterritorial | 2013 |
| Hewitson North East Roofing Ltd | Construction | 2021 |