| CDB Drylining Ltd | Construction | 2018 |
| CDJ Technical Services Limited | Information & communication | 2008 |
| Central Services & Solutions Ltd | Administrative & support | 2021 |
| Centurion Competitions Ltd | Arts & recreation | 2026 |
| Chaney Global Services Ltd | Wholesale & retail | 2008 |
| Chantry Windows Ltd | Construction | 2023 |
| Chardale Developments Limited | Construction | 2019 |
| Charles-Stanley-Dennis Ltd | Extraterritorial | 2024 |
| Charlton Construction & Developments Limited | Construction | 2020 |
| Charlton Paving Services Ltd | Construction | 2026 |
| Chens Holdings Ltd | Professional & scientific | 2026 |
| Chester Road Fish and Chips Limited | Administrative & support | 2014 |
| Cheviot Homes Limited | Real estate | 2008 |
| Cheviot Housing Limited | Real estate | 1986 |
| CHIA4UK Limited | Wholesale & retail | 2012 |
| China Foods Inc Ltd | Professional & scientific | 2022 |
| Chris Tunn Ltd | Other services | 2021 |
| Ciprian Restaurant Ltd | Hospitality | 2019 |
| CJ Wilson Offshore Services Ltd. | Professional & scientific | 2015 |
| CJM Technical Limited | Professional & scientific | 2025 |
| CL Armstrong Ltd | Energy | 2023 |
| Clarke Holland Limited | Real estate | 2007 |
| Classfit Ltd | Arts & recreation | 2015 |
| Clear Office Solutions Ltd | Real estate | 2025 |
| Clifton Road Precinct Management Company Limited | Real estate | 2012 |
| Close Racing Limited | Arts & recreation | 2017 |
| Clovelly Cars Ltd | Wholesale & retail | 2021 |
| CMG Cleaning Services Limited | Administrative & support | 2010 |
| Cmrc Engineering Ltd | Professional & scientific | 2024 |
| CN Douglas Ltd | Transport & logistics | 2026 |
| Coast to Crag Limited | Construction | 2026 |
| College Food and Wine Ltd | Wholesale & retail | 2025 |
| Comet Creative Limited | Professional & scientific | 2018 |
| Commercium Atlantic Limited | Wholesale & retail | 2026 |
| Commissioners Quay (Blyth) Management Company Limited | Real estate | 2021 |
| Complete Support Services Direct Ltd | Real estate | 2025 |
| Coneygarth Farm Ltd | Agriculture & fishing | 2017 |
| Corning Road Limited | Real estate | 2024 |
| Corroc Joinery Ltd | Construction | 2026 |
| Costarchem UK Ltd | Wholesale & retail | 2024 |
| Cowansholidaylets Limited | Hospitality | 2025 |
| CPL NE Limited | Administrative & support | 2024 |
| Craig Patterson Construction Consultant Ltd | Professional & scientific | 2017 |
| Craveable Creations Ltd | Hospitality | 2026 |
| Crown Carpets (N.E.) Limited | Manufacturing | 1996 |
| Crumpets and Sandwich Bar Ltd | Wholesale & retail | 2019 |
| Crystal Care Training Academy Ltd | Public administration | 2025 |
| CS Mechanical Connections Ltd | Mining & quarrying | 2021 |
| Cthompmechanicalservices Ltd | Construction | 2026 |
| D & a Security Limited | Administrative & support | 2007 |
| D & S Properties NE Limited | Real estate | 2025 |
| D a Financial Services Ltd | Financial services | 2015 |
| D D H Electrics Limited | Construction | 2026 |
| D Glasper Logistics Limited | Transport & logistics | 2017 |
| D S Bathrooms Ltd | Construction | 2018 |
| D&S Lyons Properties Limited | Real estate | 2026 |
| Dabole's Park Stores Limited | Wholesale & retail | 2026 |
| Danigra Ltd | Construction | 2021 |
| Darada Property Management Ltd | Real estate | 2016 |
| Darren Cleverley Properties Ltd | Real estate | 2020 |
| David Lyons Plumbing & Heating Services Limited | Construction | 2014 |
| Davison Technical Services Ltd | Professional & scientific | 2024 |
| DB Design & Draughting Limited | Professional & scientific | 2022 |
| Dbrt Ltd | Hospitality | 2022 |
| Dedicated Transport Solutions Limited | Transport & logistics | 2002 |
| Deli-Licious (of Ashington) Ltd | Hospitality | 2008 |
| Dennis Common Ltd | Extraterritorial | 2018 |
| Derwent View Reinstatement Ltd | Construction | 2023 |
| Designs Engineered Ltd | Manufacturing | 2016 |
| Dieform Precision Engineering Limited | Professional & scientific | 2002 |
| Digital Milkshake Limited | Professional & scientific | 2017 |
| Direct Autocare Ltd | Wholesale & retail | 2010 |
| Dishrupt Ltd | Hospitality | 2024 |
| DJM Speciality Services Ltd | Professional & scientific | 2026 |
| DJS Telecare Ltd | Administrative & support | 2013 |
| DL Duddridge Ltd | Mining & quarrying | 2022 |
| DMC PPS Ltd | Mining & quarrying | 2018 |
| Doherty Paving Services Limited | Construction | 2003 |
| Dollys Blyth Limited | Wholesale & retail | 2024 |
| Donatas Valmantas Consulting Limited | Professional & scientific | 2026 |
| Doors, Floors, Stairs and More Ltd | Manufacturing | 2022 |
| Doric Cake Crafts Limited | Wholesale & retail | 2016 |
| Doric Crimped Limited | Manufacturing | 2010 |
| Doric Crimped Properties Limited | Real estate | 2016 |
| Doric FPD Limited | Manufacturing | 2009 |
| DP Wilson Limited | Financial services | 2004 |
| Dpak Mechanical Ltd | Professional & scientific | 2023 |
| Dryden Services Limited | Administrative & support | 2019 |
| DS Sports Massage Ltd | Health & social care | 2026 |
| DSD Publishers Ltd | Information & communication | 2024 |
| DT Global Trade Ltd | Wholesale & retail | 2026 |
| Dunlop Project Management Ltd | Construction | 2019 |
| Durham Pharma Ltd | Wholesale & retail | 2022 |
| Dylan Mcgill Limited | Construction | 2025 |
| E and G Leisure Ashington Ltd | Hospitality | 2025 |
| EA Leisure Group Ltd | Wholesale & retail | 2017 |
| Eastern Seals (UK) Ltd | Wholesale & retail | 2007 |
| Eastern Seals Holdings Limited | Wholesale & retail | 2016 |
| Eastfield Motor Co. Ltd | Wholesale & retail | 2019 |
| Eccso Limited | Professional & scientific | 2024 |