| Campactive (Penistone) Limited | Education | 2021 |
| Campaign Central Limited | Professional & scientific | 2018 |
| Campbell Homes Ashbrow Limited | Construction | 2025 |
| Campbell Homes Darnall Limited | Construction | 2025 |
| Campbell Homes Limited | Construction | 2006 |
| Campbell Luxury Lettings Limited | Real estate | 2025 |
| Campbell Turner Ltd | Professional & scientific | 2011 |
| Camper Base Vans Limited | Wholesale & retail | 2025 |
| CAN I Breastfeed in IT? Ltd | Wholesale & retail | 2018 |
| CAN ME Ltd | Wholesale & retail | 2025 |
| CAN Studios Limited | Information & communication | 1999 |
| Canal Road Urban Village Limited | Construction | 2009 |
| Canal Street Creative Limited | Arts & recreation | 2022 |
| Canaletto Security Services Ltd | Wholesale & retail | 2024 |
| Canary Limited | Health & social care | 1995 |
| Candex Limited | Construction | 2010 |
| Cando Learning & Development Ltd | Professional & scientific | 2025 |
| Candoo Creative Limited | Professional & scientific | 2010 |
| Candy Cloud$ Ltd | Wholesale & retail | 2024 |
| Candyslam Ltd | Hospitality | 2025 |
| Canim Properties Limited | Real estate | 2025 |
| Canken Accountancy Services Limited | Professional & scientific | 2022 |
| Canklow Storage Ltd | Transport & logistics | 1985 |
| Canned Heat Limited | Administrative & support | 2020 |
| Cannon Plumbing and Heating Limited | Construction | 2018 |
| Cannon Renewables Limited | Construction | 2024 |
| Canopy Co-Operative Ltd | Administrative & support | 2025 |
| Canopy Ecology Ltd | Professional & scientific | 2019 |
| Canova Clay Limited | Manufacturing | 2024 |
| Cant Consulting Ltd | Professional & scientific | 2016 |
| Canton House Chinese Takeaway Ltd | Hospitality | 2016 |
| Cantoni Coaching Ltd | Health & social care | 2023 |
| Cantor Limited | Real estate | 2025 |
| CAP Estates Maltby Limited | Real estate | 2014 |
| CAP Family Properties Limited | Real estate | 2018 |
| Capability Rehabilitation and Work Limited | Health & social care | 2023 |
| Capasso Ltd | Hospitality | 2021 |
| Capebuild Holdings Limited | Real estate | 2025 |
| Capelli Salon (Gateford) Ltd | Other services | 2015 |
| Capex (UK) Ltd | Transport & logistics | 2014 |
| Capital Bathrooms Ltd | Construction | 2015 |
| Capital Cars UK Ltd | Wholesale & retail | 2008 |
| Capital Contract Plumbing Limited | Construction | 2009 |
| Capital Equity Holdings Limited | Construction | 2020 |
| Capital Investments and Holdings Ltd | Real estate | 2025 |
| Capital Scaffolding (Sheffield) Limited | Construction | 2024 |
| Capitol Park Property Services Limited | Real estate | 2013 |
| Caplan & Co Limited | Professional & scientific | 2006 |
| Caploitte Ltd | Information & communication | 2023 |
| Capoeira Areia DO MAR C.I.C. | Education | 2022 |
| Capper Estate Management Ltd | Real estate | 2026 |
| Capricom IT Engineering Limited | Information & communication | 2013 |
| Capricorn Commercial Limited | | 2001 |
| Capsa Solutions Limited | Professional & scientific | 2019 |
| Capstone Pharma Ltd | Health & social care | 2023 |
| Captain Clampit Limited | Other services | 2003 |
| Captain Cover Limited | Extraterritorial | 2005 |
| Captain Crew Ltd | Other services | 2024 |
| Captain Store Ltd | Wholesale & retail | 2026 |
| Captivated Ltd | Wholesale & retail | 2024 |
| Capture Connect Limited | Professional & scientific | 2025 |
| Car Bazaar Ltd | Wholesale & retail | 2019 |
| Car Care Solutions Ltd | Other services | 2013 |
| Car Charged UK Limited | Transport & logistics | 2019 |
| Car Claim Specialists Ltd | Financial services | 2023 |
| Car Connect UK Ltd | Wholesale & retail | 2014 |
| Car Exchange (Sheffield) Limited(The) | Real estate | 1987 |
| Car Express Autos Ltd | Wholesale & retail | 2025 |
| Car Placement Specialist Ltd | Wholesale & retail | 2017 |
| Car Protect Direct Limited | Other services | 2022 |
| Car Protect Limited | Professional & scientific | 1997 |
| Car Service Hamzaj Ltd | Wholesale & retail | 2020 |
| Car World Yorkshire Limited | Wholesale & retail | 2013 |
| Car-Market Limited | Wholesale & retail | 2020 |
| Carabao Capital UK Ltd | Information & communication | 2023 |
| Carabas Creative Limited | Arts & recreation | 2025 |
| Carabou Tech Ltd | Information & communication | 2018 |
| Caramalt Ltd | Manufacturing | 2025 |
| Caravan Testing Services Limited | Manufacturing | 2018 |
| Carbon Abatement Technology Engineers Limited | Professional & scientific | 2014 |
| Carbon Footprint Services Ltd | Professional & scientific | 2025 |
| Carbon Fortune Limited | Professional & scientific | 2023 |
| Carbon International Limited | Manufacturing | 1991 |
| Carbon Link Holdings Limited | Professional & scientific | 1996 |
| Carbon Products Limited | Financial services | 2022 |
| Carbrook Commercial Ltd | Wholesale & retail | 2024 |
| Carchrist Limited | Hospitality | 2023 |
| Cardamon Alliance Group Ltd | Hospitality | 2022 |
| Cardero 72 Ltd | Health & social care | 2024 |
| Cardgains Limited | Extraterritorial | 2023 |
| Cardiff Carpets Limited | Transport & logistics | 2009 |
| Cardiolegend Medtech Solutions Ltd | Manufacturing | 2025 |
| Cardora Forge Ltd | Wholesale & retail | 2026 |
| Cards & Gifts 4 U Limited | Wholesale & retail | 2008 |
| Cards & Gifts Sheffield Limited | Wholesale & retail | 2020 |
| Care 2 Care Training Services Limited | Education | 2004 |
| Care 2 Succeed Limited | Education | 2014 |
| Care 4 J Limited | Health & social care | 2010 |
| Care 4 Renters CIC | Real estate | 2022 |
| Care Absolutely Ltd | Health & social care | 2013 |