| Caprani Plumbing & Heating Limited | Construction | 2016 |
| Capsola Energy Ltd | Professional & scientific | 2021 |
| Captured Pixels Limited | Professional & scientific | 2006 |
| Car 4 U Hull Ltd | Wholesale & retail | 2021 |
| Car Clini Mechanic Ltd | Wholesale & retail | 2026 |
| Car Keys Locksmith Ltd | Wholesale & retail | 2022 |
| Car Point Hull Ltd | Wholesale & retail | 2026 |
| Car World Limited | Wholesale & retail | 2009 |
| Cara MIA Investments Limited | Real estate | 2020 |
| Carafax Holdings Limited | Financial services | 2021 |
| Carafax Limited | Wholesale & retail | 1984 |
| Caras Rend Ltd | Construction | 2024 |
| Caravan Enterprise Limited | Manufacturing | 2024 |
| Carbide (UK) Limited | Manufacturing | 2016 |
| Carbide Online Limited | Professional & scientific | 2007 |
| Carbon by Design Ltd | Construction | 2018 |
| Carbon Climate Limited | Construction | 2012 |
| Carbon Synergy Limited | Construction | 2008 |
| Cardoctor Hull Limited | Wholesale & retail | 2016 |
| Cardwell Construction Ltd | Construction | 2005 |
| Care Blueprint Associates Ltd | Professional & scientific | 2026 |
| Care Concept HCP Ltd | Health & social care | 2007 |
| Care Connection Holdings Limited | Health & social care | 2023 |
| Care Connection Partners Ltd | Health & social care | 2021 |
| Care First Clinic Limited | Wholesale & retail | 2023 |
| Care in OUR Hands Ltd | Health & social care | 2021 |
| Care Thrive Limited | Health & social care | 2026 |
| Care to LET Housing Ltd | Real estate | 2022 |
| Care to LET Investments Ltd | Real estate | 2025 |
| Care to LET Ltd | Real estate | 2017 |
| Care to Talk Limited | Information & communication | 2015 |
| CAREER5 Ltd | Education | 2020 |
| Caresta Sales Ltd | Wholesale & retail | 2019 |
| Caring Nationwide Limited | Wholesale & retail | 2006 |
| Carisbrook Drive Management Company Limited | Households | 2025 |
| Carl Hurd Joinery Ltd | Construction | 2021 |
| Carlill Property Ltd | Real estate | 2025 |
| Carlson Carriers Limited | Transport & logistics | 1997 |
| Carlton House Apartments Limited | Households | 1987 |
| Carmichael Hotel Limited | Hospitality | 2026 |
| Carmichael International Ltd | Wholesale & retail | 2013 |
| Carmichael Training & Consultancy Limited | Education | 2008 |
| Carmtech Services Limited | Professional & scientific | 2019 |
| Carnegie Heritage Centre Limited | Arts & recreation | 2009 |
| Caroline's Caterpillars Childminding Ltd | Education | 2026 |
| Carp Tackle Giveaways Ltd | Wholesale & retail | 2020 |
| Carpe Diem Projects Limited | Wholesale & retail | 2019 |
| Carr Housing Developments Limited | Real estate | 2021 |
| Carr Lane Kids Club Ltd | Education | 2010 |
| Carr Plant Hire Ltd | Construction | 2016 |
| Carroll & Crow Limited | Construction | 2025 |
| Carrpool Ltd | Construction | 2006 |
| Cars 4 Less Yorkshire Ltd | Wholesale & retail | 2015 |
| Cartello Installations Ltd | Construction | 2023 |
| Carter Drive Management Company Limited | Households | 2019 |
| CARTERCATERING2025 Ltd | Hospitality | 2025 |
| Casa Ideale Ltd | Construction | 2024 |
| Casaalquiler Ltd | Real estate | 2025 |
| Cascade (Banks House) Limited | Health & social care | 2017 |
| Cascade (Charlton House) Limited | Health & social care | 2014 |
| Cascade (Cohen House) Limited | Health & social care | 2016 |
| Cascade (Group Services) Limited | Administrative & support | 2017 |
| Cascade (Propco a) Limited | Real estate | 2026 |
| Cascade (Propco C) Limited | Real estate | 2026 |
| Cascade (Propco D) Limited | Real estate | 2026 |
| Cascade (Propco D2) Limited | Real estate | 2026 |
| Cascade (Stiles House) Limited | Health & social care | 2017 |
| Cascade Living Solutions Limited | Health & social care | 2008 |
| Casey and Black Limited | Construction | 2025 |
| Cask Homes Ltd | Real estate | 2021 |
| Caspar's Cafe Ltd | Hospitality | 2021 |
| Cassidys Sunblinds Limited | Manufacturing | 2014 |
| Cast & Catch Ltd | Agriculture & fishing | 2025 |
| Casterly Rock Ltd | Real estate | 2013 |
| Castle Bromwich Management Limited | Hospitality | 2021 |
| Castle Buildings LLP | | 2016 |
| Castle Homes Properties(Yorkshire) Limited | Real estate | 2016 |
| Castle Management Yorkshire Ltd | Real estate | 2025 |
| Castle Motors Hull Limited | Wholesale & retail | 2021 |
| Castle Rise (Hull) Limited | Construction | 2022 |
| Castle Valley Limited | Administrative & support | 2018 |
| Caststonesupplier UK Ltd | Manufacturing | 2023 |
| Casus Crop Limited | Wholesale & retail | 2022 |
| Cat Express Parcels Limited | Transport & logistics | 2010 |
| Cata AMG Ltd | Transport & logistics | 2019 |
| Catalyst Acquisitions Group Ltd | Financial services | 2024 |
| Catalyst Architects Ltd | Professional & scientific | 2020 |
| Catalyzt Limited | Extraterritorial | 2023 |
| Catchpole Kitchens & Bathrooms Ltd | Construction | 2014 |
| Catchpole Properties Limited | Real estate | 2020 |
| Cater-Care Commercial Kitchen Services Ltd | Construction | 2025 |
| Catering 4 Construction Ltd | Hospitality | 2015 |
| Catering Space UK Ltd | Real estate | 2025 |
| Catex and Co. Ltd | Administrative & support | 2018 |
| Catfoss Group Manufacturing Limited | Construction | 2013 |
| Cathedral Stone Limited | Construction | 2009 |
| Catnip Hull Ltd | Hospitality | 2018 |
| Catt Gibbons Limited | Other services | 2025 |
| Cattaneo Construction Limited | Construction | 2015 |
| Catzero Limited | Transport & logistics | 2008 |