| Crossgate Cottage Ltd | Real estate | 2020 |
| Crosslands Leisure Ltd. | Hospitality | 2017 |
| Crossman Electrical Services Limited | Administrative & support | 2024 |
| Crow Events Limited | Arts & recreation | 2020 |
| Crow Group Limited | Financial services | 2021 |
| Crown Property Lettings Ltd | Real estate | 2023 |
| Crown Property NE Limited | Real estate | 2025 |
| Crownline Trade Ltd | Wholesale & retail | 2024 |
| Crunchy Chicken and Chips Need Limited | Hospitality | 2026 |
| Crusties Pizzeria Scargill Ltd | Hospitality | 2025 |
| Crusty's Pizzeria Darlo Ltd | Hospitality | 2018 |
| Cruz Housing Ltd | Real estate | 2024 |
| CRW Hvac Limited | Professional & scientific | 2022 |
| Cryocom Ltd | Extraterritorial | 2017 |
| Cryogenic-Insulation-Services Ltd | Professional & scientific | 2011 |
| Cryosafe Services Ltd | Professional & scientific | 2021 |
| Crystal Clear Optics Ltd | Health & social care | 2023 |
| Crystal Edge Group Ltd | Wholesale & retail | 2025 |
| Crystal Galleries Limited | Manufacturing | 1983 |
| Crystal Transport Solutions Limited | Transport & logistics | 2007 |
| CS Electrical N Ltd | Construction | 2025 |
| CS Property (NE) Limited | Real estate | 2026 |
| Csbc Property Ltd | Real estate | 2025 |
| CSI Training and Events Ltd | Administrative & support | 2012 |
| Csnfo Ltd | Information & communication | 2020 |
| CT Rigging Ltd | Professional & scientific | 2017 |
| CTB ENG Tech Solutions Ltd | Other services | 2025 |
| CTC Enterprises Limited | Wholesale & retail | 2015 |
| Ctlm Property Development Ltd | Construction | 2025 |
| CTO Digital Ltd | Information & communication | 2023 |
| Ctrl (NE) Limited | Real estate | 2026 |
| CTS Commercial Vehicles Ltd | Wholesale & retail | 2021 |
| CTS Commissioning Limited | Professional & scientific | 2017 |
| CTW Properties (NE) Ltd | Real estate | 2019 |
| Cubbitz Limited | Construction | 2013 |
| Cucumber IT Ltd | Information & communication | 2017 |
| Cuddle Cubs Limited | Education | 2024 |
| Culrinn Limited | Construction | 2018 |
| Cumbria Clothing Ltd | Wholesale & retail | 2025 |
| Curated Interior Design Limited | Professional & scientific | 2021 |
| Curries Removals Transport & Technical Services Limited | Transport & logistics | 2026 |
| Curry Hurry UK Ltd | Wholesale & retail | 2024 |
| Curtain Fabric Store Ltd | Wholesale & retail | 2017 |
| Custom Slipmats Ltd | Manufacturing | 2019 |
| CUT N Craft Barbers Limited | Other services | 2021 |
| CUT N CUE Media Solutions Limited | Information & communication | 2024 |
| CUT Price Carpets and Flooring Ltd | Wholesale & retail | 2022 |
| Cute Rainbow Ltd | Wholesale & retail | 2025 |
| Cuzzi Limited | Wholesale & retail | 2025 |
| CV Pharm Ltd | Wholesale & retail | 2024 |
| CVL Housing CIC | Construction | 2022 |
| CW Engineers Ltd | Manufacturing | 2019 |
| CW Properties NE Limited | Real estate | 2018 |
| CWB Scaffolding Ltd | Construction | 2023 |
| Cwelec Ltd | Construction | 2019 |
| Cxlt Agency Ltd | Information & communication | 2025 |
| Cyberphunk Ltd | Information & communication | 2020 |
| CYBERSOL360 Ltd | Information & communication | 2024 |
| Cyrus Electrical Limited | Energy | 2023 |
| CZ Developments Ltd | Construction | 2025 |
| CZ Holdings Ltd | Financial services | 2025 |
| CZ Properties Ltd | Real estate | 2026 |
| D & D Cleaning & Property Maintenance Ltd | Administrative & support | 2025 |
| D & G Consultants Ltd | Professional & scientific | 2015 |
| D & L Holdings North Yorks Limited | Wholesale & retail | 2025 |
| D & M Offshore Ltd | Professional & scientific | 2020 |
| D & R Autos (NE) Limited | Wholesale & retail | 2013 |
| D Appleby Construction Ltd | Construction | 2021 |
| D B Fish Consultancy Limited | Professional & scientific | 2009 |
| D Brittain Ltd | Professional & scientific | 2023 |
| D Bull ENG Services Limited | Professional & scientific | 2024 |
| D Crawford Services Ltd | Construction | 2026 |
| D Grange Ltd | Wholesale & retail | 2014 |
| D J Holliday Engineering Services Limited | Professional & scientific | 2022 |
| D J Property Management (North East) Limited | Real estate | 2017 |
| D L Care Limited | Health & social care | 2009 |
| D Lofts Pipefitter Limited | Construction | 2026 |
| D Longshaw Enterprises Ltd | Information & communication | 2025 |
| D M Property NE Ltd | Real estate | 2024 |
| D Morgan Electrical Ltd | Construction | 2026 |
| D Rowley Limited | Professional & scientific | 2013 |
| D S Rope Access Solutions Limited | Construction | 2015 |
| D Siddaway Consultants Ltd | Professional & scientific | 2015 |
| D Smith Services Ltd | Construction | 2025 |
| D Turnbull Associates Limited | Administrative & support | 2022 |
| D Ward Energy Ltd | Energy | 2023 |
| D Ward Ltd | Energy | 2015 |
| D&B Properties NE Ltd | Real estate | 2025 |
| D&D Cafe African Restaurant Ltd | Hospitality | 2023 |
| D&D Contract Cleaning Ltd | Administrative & support | 2024 |
| D&D Delivery Limited | Transport & logistics | 2019 |
| D&D Enterprise Investment Ltd | Real estate | 2025 |
| D&Lm Properties Ltd | Real estate | 2024 |
| D&M Properties (Teesside) Limited | Real estate | 2018 |
| D&M Properties North East Ltd | Real estate | 2020 |
| D&S NE Limited | Wholesale & retail | 2023 |
| D&S Travel Limited | Transport & logistics | 2016 |
| D&T Nails Limited | Other services | 2022 |
| D-Mand Offshore Engineering Ltd | Construction | 2014 |
| D-Regal African Foodstore Ltd | Wholesale & retail | 2025 |