| Charlie Lewis Limited | Wholesale & retail | 2025 |
| Chase Renovations Limited | Construction | 2020 |
| Chase Risk Management Limited | Professional & scientific | 2018 |
| Chawk Projects Ltd | Administrative & support | 2016 |
| Cheer Starz Academy Ltd | Arts & recreation | 2023 |
| Chef Supply Ltd | Hospitality | 2025 |
| CHELCAM1982 Ltd | Health & social care | 2020 |
| Chelwood House (GS) Limited | Real estate | 2024 |
| Cheminsight Ltd | Professional & scientific | 2025 |
| Chemseal Solutions Ltd | Wholesale & retail | 2010 |
| Cherie Mcbean Consultancy Limited | Professional & scientific | 2026 |
| Cherish With Care Limited | Health & social care | 2025 |
| Cherry Blossom Boutique Limited | Wholesale & retail | 2025 |
| Cherry Park Limited | Other services | 2015 |
| Cherry Pick People Limited | Administrative & support | 2008 |
| Chestermadrid Ltd | Health & social care | 2023 |
| Chic and Crafty Limited | Wholesale & retail | 2023 |
| Chico’S Food and Beverage Limited | Hospitality | 2024 |
| Child & Adult Therapy Solutions Limited | Health & social care | 2013 |
| Chloe's Counselling & Training Ltd | Health & social care | 2025 |
| Chris Burton Limited | Construction | 2026 |
| Christie Networks Limited | Construction | 2018 |
| Christopher Cheung Logistics Ltd | Transport & logistics | 2025 |
| Christopher Gair Ltd | Manufacturing | 2019 |
| CHT Developments Limited | Construction | 2006 |
| Chuk Anya Ltd | Information & communication | 2025 |
| Chunnam Offshore Wind Services Limited | Manufacturing | 2018 |
| Church View Restaurant Ltd | Hospitality | 2014 |
| Chwp Limited | Financial services | 2026 |
| Cian Construction Company Limited | Financial services | 2013 |
| Cian James Limited | Real estate | 2018 |
| Cigar Cigar Music Limited | Arts & recreation | 2021 |
| Cioby Serv Ltd | Transport & logistics | 2025 |
| Cipher Medical Consultancy Limited | Education | 2015 |
| Circle of Confusion Films Limited | Information & communication | 2016 |
| Circular Safe Limited | Water & waste | 2025 |
| CJ Management Solutions Limited | Professional & scientific | 2016 |
| CJ Specialist Construction Services Limited | Construction | 2009 |
| CJ Tech Limited | Manufacturing | 2016 |
| CJE Engineering (NE) Ltd | Professional & scientific | 2023 |
| Cjpf Engineering Ltd | Construction | 2019 |
| CJR Elevators Ltd | Manufacturing | 2021 |
| CJS Empresa Ltd | Wholesale & retail | 2026 |
| CJS Geology Limited | Professional & scientific | 2011 |
| CJW Enterprises Ltd | Health & social care | 2024 |
| CK Drywall Limited | Construction | 2016 |
| CK Electrical Access Limited | Mining & quarrying | 2016 |
| CK Healthcare Limited | Administrative & support | 2016 |
| CK Plumbing and Heating Ltd | Construction | 2008 |
| CK Property Group Ltd | Households | 2024 |
| CKE Supplies Ltd | Wholesale & retail | 2026 |
| CKH Properties Ltd | Real estate | 2016 |
| CL & SON Engineering Limited | Administrative & support | 2015 |
| Claire J Baker Limited | Administrative & support | 2022 |
| Clare Watson Teesside Ltd | Professional & scientific | 2025 |
| Clarendon Local Retail Limited | Wholesale & retail | 2015 |
| Clarity Commercial Consulting Ltd | Professional & scientific | 2020 |
| Clarity Insights Ltd | Professional & scientific | 2026 |
| Clarity Utility Partners Ltd | Professional & scientific | 2025 |
| Clark Lifting Services Ltd | Construction | 2024 |
| Clark Propery Holdings Ltd | Real estate | 2020 |
| Clarke Clark and Davidson Limited | Real estate | 2016 |
| Clarkys Properties Limited | Real estate | 2017 |
| Class Fundraising Limited | Manufacturing | 2010 |
| Classic Admin Solutions Ltd | Administrative & support | 2020 |
| Classic Resourcesuk Ltd | Health & social care | 2016 |
| Classida Ltd | Information & communication | 2024 |
| Claud's H I & M Limited | Construction | 2018 |
| Claxton Estates Limited | Real estate | 2015 |
| Clayton House Care Ltd | Health & social care | 2015 |
| CLC Care Services Ltd | Health & social care | 2025 |
| CLC Health & Aesthetics Limited | Other services | 2022 |
| Clean Finish Ltd | Administrative & support | 2024 |
| Cleaning and Support Services Ltd | Administrative & support | 2007 |
| Cleaning Products Limited | Wholesale & retail | 2020 |
| Cleanpay Limited | Information & communication | 2019 |
| Cleanwise Cleaning Services Ltd | Administrative & support | 2026 |
| Clear Debt Direct Ltd | Financial services | 2007 |
| Clear Homes Group Limited | Construction | 2025 |
| Clear IT! (Teesside) Ltd | Water & waste | 2016 |
| Clear Routing Solutions Limited | Professional & scientific | 2022 |
| Clear View Exterior Cleaning Ltd | Water & waste | 2016 |
| Clear Vision Inspection Ltd | Construction | 2021 |
| Clearline Plumbing & Heating Ltd | Construction | 2025 |
| Clearsix Ltd | Professional & scientific | 2022 |
| Clearskies Cyber Ltd | Information & communication | 2025 |
| Clearview Cardiac Services Ltd | Health & social care | 2024 |
| Clearwashuk Ltd | Administrative & support | 2023 |
| Cleveland 1963 Limited | Extraterritorial | 2013 |
| Cleveland Alzheimer's Residential Centre Limited | Health & social care | 1989 |
| Cleveland Bridge UK Limited | Construction | 1999 |
| Cleveland Care at Home Limited | Health & social care | 2014 |
| Cleveland Commissioning Ltd | Professional & scientific | 2024 |
| Cleveland Cricket Academy Ltd | Education | 2023 |
| Cleveland Group (Hire and Sales) Limited | Transport & logistics | 2011 |
| Cleveland Homes (NO.1) Limited | Real estate | 1988 |
| Cleveland Homes (NO.2) Limited | Real estate | 1990 |
| Cleveland Homes (NO.3) Limited | Real estate | 1992 |
| Cleveland Homes (NO.4) Limited | Real estate | 1993 |
| Cleveland Homes (NO.5) Limited | Real estate | 1993 |