| Creative Solutions (Europe) Limited | Wholesale & retail | 2005 |
| Cree Concrete Ltd | Manufacturing | 2025 |
| Creoplan Ltd | Information & communication | 2002 |
| Crescent Court (Willerby) Limited | Households | 2006 |
| Crest Holding Limited | Real estate | 2021 |
| Crest Lets Ltd | Real estate | 2011 |
| Crest Performance Ltd | Wholesale & retail | 2020 |
| Crestmont Investments Limited | Real estate | 2025 |
| Crete Foods Ltd | Hospitality | 2023 |
| Crewe Arms Management Limited | Hospitality | 2021 |
| Creyke Close (Management) Limited | Real estate | 1965 |
| Crime Stop Security Systems Limited | Administrative & support | 1997 |
| Crimsonmoon (Hull) Limited | Professional & scientific | 2008 |
| Crinkle Court Maintenance Limited | Households | 1978 |
| Cristiana VIC Ltd | Construction | 2023 |
| CRK Engineering Limited | Manufacturing | 2013 |
| CRM Flooring of Doncaster Ltd | Construction | 2026 |
| Crompton Estates Ltd | Real estate | 2002 |
| Crossco Timber Limited | Financial services | 2025 |
| Crossco Timber Subsidiary 1 Limited | Wholesale & retail | 2025 |
| Crossco Timber Subsidiary 2 Limited | Wholesale & retail | 2025 |
| Crossfield Flats Association Limited(The) | Real estate | 1985 |
| Crossfit Hull Ltd | Arts & recreation | 2013 |
| Crossfit Humber Ltd | Arts & recreation | 2015 |
| Crowberry Wood Limited | Wholesale & retail | 2022 |
| Crowdrop Ltd | Wholesale & retail | 2024 |
| Crown Chambers Property Ltd | Construction | 2022 |
| Crown Chambers Services Limited | Professional & scientific | 2020 |
| Crown Felt Roofing Limited | Construction | 2021 |
| Crown Machining Services Limited | Manufacturing | 1991 |
| Crown to Sole Ltd | Health & social care | 2022 |
| Crown Windows & Doors (Hull) Limited | Construction | 2020 |
| Crowther Court Management (Swanland) Limited | Households | 1996 |
| CRS Roofing Specialists Ltd | Construction | 2026 |
| Cruitem Limited | Administrative & support | 2017 |
| Crumpton & Co Ltd. | Professional & scientific | 2003 |
| Crusty COB Instore Bakery Ltd | Hospitality | 2007 |
| CRW Entertainment Group Limited | Professional & scientific | 2025 |
| Crypt INK Ltd | Other services | 2023 |
| Cryptid VPN Ltd | Information & communication | 2026 |
| Crystal Clear (Hull) Limited | Administrative & support | 2023 |
| Crystal Clear Professional Cleaning Services Limited | Administrative & support | 2024 |
| CS Beauty Academy Ltd | Other services | 2019 |
| CS Inspection Limited | Professional & scientific | 2020 |
| CS Legal Ltd | Professional & scientific | 2015 |
| CS Motors Hull Ltd | Wholesale & retail | 2019 |
| CS Scents Limited | Wholesale & retail | 2025 |
| CS Tyres Limited | Financial services | 2020 |
| CS Wind Europe Limited | Construction | 2014 |
| CSB Consultancy Services Ltd | Professional & scientific | 2022 |
| CSC (Specialised Vehicles) Limited | Extraterritorial | 1995 |
| CSM Property Investments Ltd | Real estate | 2023 |
| CT Global (UK) Limited | Wholesale & retail | 2005 |
| CT Holdings & Services Ltd | Other services | 2018 |
| CTC Moling Ltd | Construction | 2022 |
| Ctewellbeing & Mentalhealth Ltd | Information & communication | 2026 |
| CTJ Fire Doors Limited | Manufacturing | 2019 |
| CTL Planning Limited | Administrative & support | 2016 |
| Ctop Limited | Information & communication | 2011 |
| Ctrl Civils Ltd | Construction | 2023 |
| CTS (Shopfitting) Limited | Construction | 1998 |
| CTS Hull Limited | Extraterritorial | 2009 |
| Ctsr Construction Limited | Construction | 2016 |
| CU Support CIC | Hospitality | 2021 |
| Cuba Consultants Ltd | Professional & scientific | 2004 |
| Cuban Petes Ltd | Hospitality | 2022 |
| Cubby Hull Limited | Real estate | 2017 |
| Cube 5 Global Limited | Health & social care | 2024 |
| Cubes Auto Ltd | Wholesale & retail | 2026 |
| CUK Sales Ltd | Wholesale & retail | 2019 |
| Culinan Ltd | Transport & logistics | 2023 |
| Cumbrian Escape Properties Limited | Real estate | 2026 |
| Cunicon Engineering Services Limited | Manufacturing | 2012 |
| Cunicon Ltd | Manufacturing | 2005 |
| CUNN1NG Ltd | Transport & logistics | 2015 |
| Cunning Innovations Ltd | Construction | 2017 |
| Curamach Limited | Professional & scientific | 2026 |
| Curew Care Ltd | Health & social care | 2026 |
| Curium Digital Ltd | Professional & scientific | 2024 |
| Curlcombo Ltd | Wholesale & retail | 2025 |
| Curport Properties Limited | Construction | 2008 |
| Curry Chatty Ltd | Hospitality | 2025 |
| Curry Leaf(Yorkshire) Limited | Hospitality | 2024 |
| Curt Haulage Ltd | Transport & logistics | 2024 |
| Curt on Drive Ltd | Administrative & support | 2025 |
| Curtis & Curtis Ltd | Hospitality | 2026 |
| Curtis Cant Ventures Limited | Information & communication | 2016 |
| Curtis Construction and Property Limited | Construction | 2017 |
| Custom Carpentry Crafters Limited | Manufacturing | 2025 |
| Custom Steel Fabrications Ltd | Construction | 2012 |
| CUT and Coat Ltd | Manufacturing | 2025 |
| Cutique Unisex Salon Limited | Other services | 2012 |
| Cutx and Shave Ltd | Other services | 2023 |
| Cvita Limited | Administrative & support | 2015 |
| CYA Properties Limited | Real estate | 2023 |
| Cyan Renewables (UK) Holdings Limited | Financial services | 2023 |
| Cyan-Sentinel Holdings Limited | Financial services | 2023 |
| Cybro Holdings Ltd | Real estate | 2017 |
| Cyriglo Ltd | Real estate | 2023 |
| C’Lux Nails & Beauty Ltd | Other services | 2025 |