| Cleanwave (NE) Ltd | Administrative & support | 2026 |
| Clear and Loud Limited | Arts & recreation | 2013 |
| Clear Business Outcome Limited | Professional & scientific | 2010 |
| Clear Divide Glass Partitions Ltd | Construction | 2024 |
| Clear EAR North East Ltd | Health & social care | 2026 |
| Clear Energy Consulting Ltd | Administrative & support | 2017 |
| Clear Language Interpreters Limited | Information & communication | 2026 |
| Clear New Media Ltd | Information & communication | 2010 |
| Clear Pest Control Ltd | Administrative & support | 2025 |
| Clear View Rope Access Window Cleaning Ltd | Administrative & support | 2019 |
| Cleara Water Ltd | Wholesale & retail | 2025 |
| Clearance AMZ Ltd | Wholesale & retail | 2024 |
| Clearancesale Ltd | Wholesale & retail | 2025 |
| Clearlingo Ltd | Professional & scientific | 2019 |
| Clearpath Accounts UK Limited | Professional & scientific | 2025 |
| Clearplanit Ltd | Information & communication | 2015 |
| Clearview Balustrades (North East) Ltd | Construction | 2026 |
| Clearvue Contractors Ltd | Construction | 2025 |
| Clearword Media Ltd | Information & communication | 2025 |
| Cleekers Ltd | Manufacturing | 2025 |
| Clelands Shipbuilders Limited | | 1957 |
| Clelland Limited | Construction | 2020 |
| Clembridge Asset Holdings Ltd | Real estate | 2026 |
| Clemency Wright Consulting Limited | Professional & scientific | 2013 |
| Clems Kitchen Group Ltd | Hospitality | 2026 |
| Clennell Education Solutions Limited | Education | 2014 |
| Clentec Service Limited | Manufacturing | 2009 |
| Cleva Europe Ltd | Wholesale & retail | 2017 |
| Cleva Snax Vending Limited | Wholesale & retail | 2025 |
| Cleveland Ceilings & Partitions Limited | Construction | 2005 |
| CLG Wind Ltd | Professional & scientific | 2023 |
| Click 4 Veterans Limited | Information & communication | 2022 |
| Click Shopping Ltd | Wholesale & retail | 2018 |
| Clickbazaar Ltd | Wholesale & retail | 2025 |
| Clicklandingpages Limited | Professional & scientific | 2020 |
| Client Confidence Ltd | Other services | 2021 |
| Cliff Burr Sound Services Ltd | Information & communication | 2009 |
| Cliff Harrington Limited | Administrative & support | 2023 |
| Clifford Renewable Heating Solutions Ltd | Construction | 2026 |
| Clifton Property Investments Limited | Real estate | 2012 |
| Climalysis Limited | Professional & scientific | 2021 |
| Climate Cooling Services Limited | Other services | 2003 |
| Climb Newcastle Limited | Arts & recreation | 2007 |
| Climbahub Limited | Arts & recreation | 2024 |
| Clinchsparkles Ltd | Administrative & support | 2025 |
| Clinfield Limited | Education | 2010 |
| Clini-Hub Limited | Information & communication | 2021 |
| Clinic Naturae Limited | Health & social care | 2005 |
| Clinical Supervision - North East Limited | Health & social care | 2018 |
| Clint Leisure Ltd | Hospitality | 2014 |
| Clive Jamieson Ltd | Wholesale & retail | 2009 |
| Cljw Ltd | Professional & scientific | 2024 |
| CLK Aesthetics Ltd | Other services | 2024 |
| CLM Haulage Ltd | Transport & logistics | 2016 |
| CLO Aesthetics Ltd | Other services | 2025 |
| Cloc Foods Limited | Wholesale & retail | 2023 |
| Clockwise Healthcare Solutions Limited | Administrative & support | 2023 |
| Clockwork Dreams Limited | Information & communication | 2016 |
| Cloisters Corbridge (Management) Limited | Real estate | 2000 |
| Close Grips Limited | Information & communication | 2018 |
| Close House Golf Club Limited | Arts & recreation | 2007 |
| Closewalk Limited | Real estate | 1965 |
| Clothco 07001 Limited | Manufacturing | 1919 |
| Cloud Beginner Limited | Information & communication | 2024 |
| Cloud Data Service Limited | Information & communication | 2011 |
| Cloud Estates Ltd | Real estate | 2013 |
| Cloud Houses Limited | Arts & recreation | 2009 |
| Cloud Leisure Ltd | Hospitality | 2018 |
| Cloud MSD Ltd | Information & communication | 2019 |
| Cloud Services Team Ltd. | Information & communication | 2018 |
| Cloud Syntax Ltd | Information & communication | 2013 |
| Cloudbook Online Accountants Ltd | Professional & scientific | 2014 |
| Clouded Dreams Limited | Wholesale & retail | 2024 |
| CLOUDS90 Ltd | Wholesale & retail | 2024 |
| Cloudseekers Limited | Administrative & support | 2020 |
| Cloudserv Limited | Information & communication | 2022 |
| Cloudstream Dynamics Ltd | Information & communication | 2023 |
| Clouston Group Ltd | Professional & scientific | 1994 |
| Clouston Landbased Contracting Ltd | Agriculture & fishing | 2025 |
| Clover Bank (Birmingham New Road) Management Company Limited | Households | 2009 |
| Cloverdale System Integration Ltd. | Construction | 2011 |
| Cloverfield Projects Ltd | Professional & scientific | 2011 |
| Cloviana Ltd | Information & communication | 2025 |
| Clowning Around Ltd | Education | 2000 |
| Clpp Investments Limited | Real estate | 2019 |
| CLS Healthcare Limited | Real estate | 2016 |
| Club 1933 Limited | Professional & scientific | 2025 |
| Club 1984 Limited | Wholesale & retail | 2019 |
| Club Nine One Two Food & Desserts Ltd | Hospitality | 2025 |
| Club Pilates Limited | Arts & recreation | 2023 |
| Club Prosecco Ltd | Hospitality | 2019 |
| Club XS Leisure Limited | Hospitality | 2022 |
| Clubhouse Gaming CIC | Administrative & support | 2022 |
| Clubhouse Gyms Ltd | Arts & recreation | 2019 |
| Clubhouse Holdings Newcastle Limited | Financial services | 2025 |
| Clubhouse Print Newcastle Limited | Manufacturing | 2025 |
| Cluckco Foods Ltd | Hospitality | 2025 |
| Clusters Traders Ltd | Wholesale & retail | 2023 |
| Clutch N Go Limited | Education | 2023 |
| CLW (UK) Ltd | Professional & scientific | 2012 |