| Clearline Property Holdings Limited | Real estate | 2022 |
| Clearview Commercial Services Ltd | Professional & scientific | 2026 |
| Clearway Environmental Services (North East) Limited | Administrative & support | 2026 |
| Clearway Environmental Services Limited | Administrative & support | 1982 |
| Clever IT Solutions (North East) Limited | Other services | 2011 |
| Clever Kids Project Ltd | Professional & scientific | 2017 |
| Cleverclogs Training Ltd | Education | 2023 |
| Click Done Limited | Professional & scientific | 2025 |
| Clicka Jobs Ltd | Administrative & support | 2004 |
| Clickabletrades Limited | Wholesale & retail | 2025 |
| Cliff Pratt Limited | Wholesale & retail | 1999 |
| Cliff Top Roofing Ltd | Construction | 2026 |
| Clinic One Hundred and Four Ltd | Other services | 1998 |
| Clinical Software Partners Ltd | Information & communication | 2025 |
| Clinipath Limited | Health & social care | 2010 |
| CLJ Hair Limited | Other services | 2019 |
| CLM Electrical (East Yorkshire) Limited | Construction | 2024 |
| Clodette Ltd | Professional & scientific | 2024 |
| Clothing Stock Limited | Wholesale & retail | 2023 |
| Cloud and Data Limited | Information & communication | 2025 |
| Cloud Design Box Ltd | Information & communication | 2015 |
| Cloud Payments Ltd | Information & communication | 2018 |
| Cloudqube Devops Consulting Limited | Information & communication | 2019 |
| Clough Road Hand Car Wash 1 Ltd | Administrative & support | 2025 |
| Clover Assets Management Limited | Administrative & support | 2014 |
| Clover Dairies Limited | | 1900 |
| CLP Fabrication Ltd | Manufacturing | 2023 |
| CLR Rooms Ltd | Manufacturing | 2022 |
| CLS Joinery Services Limited | Construction | 2019 |
| Clubbed Thumb Limited | Information & communication | 2018 |
| Clucking Oinks Ltd | Hospitality | 2017 |
| Clyr Skin Holdings Ltd | Professional & scientific | 2026 |
| Clyr Skin Ltd | Administrative & support | 2024 |
| CM Business Solutionz Limited | Professional & scientific | 2013 |
| CM Electrical (Hull) Limited | Construction | 2025 |
| Cma-Uk Ltd | Construction | 2026 |
| Cmac Tech Services Limited | Manufacturing | 2026 |
| Cmap Transport Ltd | Transport & logistics | 2026 |
| CMC Lettings (Hull) Limited | Real estate | 2024 |
| CMF Communications (Hull) Ltd | Professional & scientific | 2014 |
| CMG Medical Equipment Ltd | Wholesale & retail | 2023 |
| Cmhla Limited | Hospitality | 2023 |
| CMI Scarlet Ltd | Hospitality | 2011 |
| CMK Power Solutions Limited | Construction | 2016 |
| CMM Contractors Limited | Construction | 2009 |
| CMM Property Holdings Limited | Households | 2024 |
| CMP Legal Services Limited | Professional & scientific | 2022 |
| CMS Holdings (Yorkshire) Limited | Construction | 2015 |
| CMS Supplies Limited | Wholesale & retail | 2021 |
| Cmsm Group Ltd | Real estate | 2026 |
| CN . Scaffold Services Limited | Construction | 2016 |
| CNM Electrical Ltd | Construction | 2013 |
| CNU Property Ltd | Real estate | 2023 |
| Co-Development (Hull) Ltd | Information & communication | 2015 |
| Co. North Limited | Professional & scientific | 2026 |
| Coach Craig Performance Coaching Ltd | Other services | 2017 |
| Coaching Collective HQ Limited | Arts & recreation | 2025 |
| Coachman Caravan Company Limited | Manufacturing | 1986 |
| Coachman Group Limited | Financial services | 2016 |
| Coachman Holdings Limited | Financial services | 2001 |
| Cobble Road Ltd | Hospitality | 2017 |
| Cobra Fire and Security Ltd | Administrative & support | 2021 |
| Coburn Construction Ltd | Construction | 2021 |
| Coburn Developments Ltd | Construction | 2025 |
| Cock and Bell Preston Limited | Hospitality | 2026 |
| Cock of the Walk Limited | Manufacturing | 2026 |
| Cock of the Walk Regalia Ltd | Manufacturing | 2026 |
| Cockshutt Estates Limited | Real estate | 2025 |
| Coco Homes (Yorkshire) Limited | Real estate | 2020 |
| Cocoa Bakery Limited | Manufacturing | 2017 |
| Code & Deploy Limited | Information & communication | 2021 |
| Code Crafter Academy Ltd | Education | 2025 |
| CODE418 Limited | Information & communication | 2021 |
| Codebase Consulting Limited | Information & communication | 2016 |
| Codie's Dollhouse Limited | Other services | 2024 |
| Cody Drameh Limited | Other services | 2022 |
| Coffee Acts Limited | Hospitality | 2023 |
| Coffee Beeans Ltd | Hospitality | 2024 |
| Coffee House Cafe Limited | Hospitality | 1987 |
| Coffee Luxe Limited | Hospitality | 2024 |
| Cogan Chambers Management Limited | Households | 2003 |
| Coghill Boxing Ltd | Arts & recreation | 2023 |
| Cogz Tyres Limited | Wholesale & retail | 2024 |
| COL Dixon Electrical Ltd | Construction | 2024 |
| Cold Moor Property Services Limited | Real estate | 2020 |
| Cole Property Development Ltd | Administrative & support | 2017 |
| Coleta Limited | Administrative & support | 2025 |
| Colin Jennings Consultancy Limited | Information & communication | 1997 |
| Colin Russell Heating & Plumbing Limited | Construction | 2003 |
| Coliseum of Chaos Ltd | Education | 2025 |
| Collectibles U.K. Limited | Wholesale & retail | 2021 |
| Collingwood Homes Ltd | Real estate | 2004 |
| Collis Energy Solutions Ltd | Construction | 2022 |
| Collscaff Limited | Administrative & support | 2017 |
| Collscaff Properties Limited | Real estate | 2025 |
| Colosseum of Chaos Ltd | Education | 2025 |
| Colour Creation York Limited | Construction | 2020 |
| Colour Flow UK Limited | Manufacturing | 2002 |
| Colour Scene (Yorkshire) Limited | Construction | 2009 |
| Colpin Limited | Construction | 2015 |