| Clarkguard Solutions Limited | Administrative & support | 2025 |
| Clart About Ltd | Hospitality | 2014 |
| Class ACT Coffee Shop Ltd | Hospitality | 2021 |
| Clive Nicholson Limited | Real estate | 2008 |
| Close Caterers (NE) Ltd | Hospitality | 2015 |
| CM Flooring Limited | Construction | 2012 |
| Coast & Country Stays NE Limited | Hospitality | 2026 |
| Code Aces Consultancy Limited | Professional & scientific | 2020 |
| Code Jutsu Ltd | Information & communication | 2016 |
| Colin Willis Haulage Limited | Transport & logistics | 2001 |
| Community Wins Lottery Limited | Arts & recreation | 2026 |
| Compass NE Limited | Construction | 2019 |
| Complete Flooring Solutions NE Ltd | Wholesale & retail | 2014 |
| Concept Auto Detailing Ltd | Wholesale & retail | 2025 |
| Connecting Professional Firms Ltd | Administrative & support | 2010 |
| Connor Forestry Limited | Agriculture & fishing | 2019 |
| Consett & District Golf Club,Limited(The) | Arts & recreation | 1968 |
| Consett Accountants Limited | Professional & scientific | 2018 |
| Consett and District Heritage and Arts Community Interest Company | Arts & recreation | 2019 |
| Consett Association Football Club Ltd | Arts & recreation | 2026 |
| Consett Car & Commercial Ltd | Wholesale & retail | 2019 |
| Consett Caravan & Container Storage Ltd | Real estate | 2013 |
| Consett Cars Ltd | Transport & logistics | 2020 |
| Consett Delicatessen Ltd | Wholesale & retail | 2016 |
| Consett Food and Wine Ltd | Wholesale & retail | 2019 |
| Consett GAS Stoves & Bathrooms Limited | Construction | 2017 |
| Consett Hand Car Wash Ltd | Wholesale & retail | 2016 |
| Consett Locksmiths Ltd | Administrative & support | 2023 |
| Consett Medical Ltd | Health & social care | 2012 |
| Consett Steel Works Ltd | Manufacturing | 2021 |
| Consett Tile Centre Limited | Construction | 2020 |
| Consett Towbars Ltd | Wholesale & retail | 2022 |
| Continuum Community Support and Cohesion Community Interest Company | Professional & scientific | 2008 |
| Convergent Knowledge Ltd | Information & communication | 2012 |
| Cool Blue College Ltd | Education | 1993 |
| Cool Cat Bars Limited | Hospitality | 2018 |
| Cophr Ltd | Real estate | 2025 |
| Corbridge Road Garage Limited | Wholesale & retail | 2008 |
| Corinthian Security and Medical Services Ltd | Professional & scientific | 2025 |
| County and Northern Limited | Construction | 1988 |
| County Composite Doors Limited | Construction | 2015 |
| Cowan Property Ltd | Real estate | 2017 |
| Cowan Subsea Limited | Real estate | 2013 |
| Coztea Ltd | Manufacturing | 2025 |
| CPF Advice Limited | Financial services | 2003 |
| CR Futures Ltd | Wholesale & retail | 2024 |
| Craig Morgan Psychotherapy Ltd | Health & social care | 2022 |
| Creative Kitchen Franchising Ltd | Professional & scientific | 2022 |
| Creative Kitchen HQ Ltd | Hospitality | 2022 |
| Creed Mixed Martial Arts C.I.C. | Education | 2025 |
| Creed MMA Limited | Arts & recreation | 2024 |
| Cresca Care Recruitment Ltd | Professional & scientific | 2026 |
| Cresco Medical Finances Ltd | Professional & scientific | 2015 |
| CRG Commercial Ltd | Construction | 2025 |
| CRG Construction Ltd | Construction | 2024 |
| CRH Telecom Ltd | Information & communication | 2025 |
| Cristallina Cleaning Ltd | Administrative & support | 2026 |
| Croft Business Services (UK) Ltd | Administrative & support | 2010 |
| Croft Smart Homes UK Limited | Information & communication | 2026 |
| Cross Country Canines Ltd | Agriculture & fishing | 2024 |
| Crown and Crossed Swords Limited | Hospitality | 2020 |
| Crystel Associates Ltd | Other services | 2008 |
| Cuniculo Ltd | Information & communication | 2007 |
| Curlylox UK Ltd | Other services | 2020 |
| Current Zero Ltd | Professional & scientific | 2023 |
| CV Joinery (NE) Limited | Construction | 2022 |
| CV Lettings Ltd | Real estate | 2022 |
| CVC Roofing Ltd | Construction | 2026 |
| CWE Access Limited | Construction | 2014 |
| Cybernought Ltd | Professional & scientific | 2026 |
| Cygnet Images Limited | Professional & scientific | 2003 |
| D & H Barrett Holdings Ltd | Financial services | 2026 |
| D & L Property Solutions Ltd | Mining & quarrying | 2019 |
| D a Access Ltd | Professional & scientific | 2014 |
| D a Hire Ltd | Transport & logistics | 2016 |
| D Ghee Holdings Limited | Financial services | 2023 |
| D J Routledge Haulage Limited | Construction | 2008 |
| D M Maintenance Ltd | Construction | 2021 |
| D Made Limited | Construction | 2025 |
| D S Meiklejohn Creative Solutions Ltd | Construction | 2012 |
| D.I.B Joinery Ltd | Manufacturing | 2018 |
| D3 Care Ltd | Health & social care | 2013 |
| Dancom Developments Limited | Real estate | 2015 |
| Danielle's Decorating Ltd | Real estate | 2026 |
| Darelath Limited | Information & communication | 2026 |
| Darren Mccabe Ltd | Health & social care | 2022 |
| Dave Black Construction Limited | Construction | 1990 |
| Dave Clarke Associates Ltd | Professional & scientific | 2026 |
| David Stanley Blinds & Shutters Limited | Professional & scientific | 2021 |
| David Taylor Dental Ltd | Health & social care | 2024 |
| Davies Construction NE Ltd | Construction | 2025 |
| Davies Group UK Holdings Ltd | Financial services | 2026 |
| Davison Holdings Limited | Real estate | 2016 |
| Day-Ault Solutions Limited | Information & communication | 2013 |
| DB Block Paving Limited | Construction | 2003 |
| DB Painting Contractors Ltd | Construction | 2026 |
| DC Installations (NE) Limited | Construction | 2018 |
| DC Studio's Exercise Performance & Healthy Living Limited | Other services | 2018 |
| DDR Security Services Ltd | Professional & scientific | 2022 |
| Debbie Gaskin ISW Limited | Health & social care | 2013 |