| Chop Suey Takeaway Ltd | Hospitality | 2025 |
| Chosen Travel Ltd | Transport & logistics | 2018 |
| CHR Facility Solutions Ltd | Administrative & support | 2025 |
| Chris Brierley Surveyors Ltd | Professional & scientific | 2020 |
| Chris H Driving School Limited | Education | 2025 |
| Chris Milton Commercial Services Ltd | Wholesale & retail | 2020 |
| Chris Yachting Ltd | Administrative & support | 2012 |
| Christie's Hair & Treatment City Limited | Other services | 2017 |
| Chrupek Ltd | Information & communication | 2016 |
| Chrysalis Talent Development Limited | Administrative & support | 2024 |
| Chuffin Good Homes Limited | Real estate | 2023 |
| Chunky Hamster Ltd | Arts & recreation | 2015 |
| Church Lads' and Church Girls' Brigade(The) | Health & social care | 1978 |
| Church Lane Services Ltd | Construction | 2023 |
| Churchill & Felstead Limited | Hospitality | 2018 |
| CHW Group Ltd | Professional & scientific | 2025 |
| CI ABF I Northwich Holdco Ltd | Financial services | 2024 |
| CI Aminth Holdco Ltd | Financial services | 2021 |
| CI Cronos Holdco Ltd | Financial services | 2022 |
| CI III Lostock EFW Holding Limited | Financial services | 2017 |
| CI III Lostock EFW Limited | Financial services | 2017 |
| CI IV Arrow Holdco Ltd | Financial services | 2021 |
| CI IV RYE Holdco Ltd | Financial services | 2022 |
| CI IV RYE Lender Ltd | Financial services | 2022 |
| CI IV Slough HOLDCO1 Ltd | Financial services | 2020 |
| CI IV Slough HOLDCO2 Ltd | Financial services | 2020 |
| CI IV Spring Holdco a Ltd | Financial services | 2022 |
| CI IV Spring Holdco B Ltd | Financial services | 2023 |
| CI IV Spring Holdco C Ltd | Financial services | 2023 |
| CI IV Spring II Holdco a Ltd | Financial services | 2022 |
| CI Tarchon Holdco Ltd | Financial services | 2022 |
| CI V Dragon Holdco 2 Ltd | Financial services | 2023 |
| CI V Dragon Lender Ltd | Financial services | 2021 |
| CI V Dragon Topco Ltd | Financial services | 2023 |
| CI V Longbow Topco Limited | Financial services | 2026 |
| CI V Morecambe Topco Limited | Financial services | 2023 |
| CI V Porto Topco Limited | Financial services | 2023 |
| CI V RYE Topco Ltd | Financial services | 2023 |
| CI V South West Wind Holdco Ltd | Financial services | 2024 |
| Cial Ltd | Hospitality | 2022 |
| CII Holdco Ltd | Financial services | 2013 |
| Cinamon Rotherham Ltd | Hospitality | 2025 |
| Cinienergy Ltd | Professional & scientific | 2023 |
| CIP FS UK Ltd. | Professional & scientific | 2025 |
| CIP Platform Solutions UK Ltd. | Professional & scientific | 2025 |
| CIP Terra Technologies UK Ltd. | Professional & scientific | 2025 |
| Cirrus Technical Limited | Information & communication | 2025 |
| Ciswo Charitable Property Services Trust | Real estate | 2014 |
| Citrine Property Investments Limited | Real estate | 2022 |
| City Driving School Group Ltd | Education | 2026 |
| City Furniture Ltd | Manufacturing | 2023 |
| City of Sheffield Gymnastics Club C.I.C. | Arts & recreation | 2023 |
| City Roost Ltd | Real estate | 2018 |
| City View Productions Ltd | Arts & recreation | 2018 |
| City Wide Mechanical Services Ltd | Construction | 2013 |
| Cityparcel Ltd | Transport & logistics | 2023 |
| Civic Plumbing Solutions Ltd | Construction | 2024 |
| Civil Consult Ltd | Construction | 2024 |
| Civro Limited | Information & communication | 2012 |
| CJ Motors Auto Refinisher Ltd | Wholesale & retail | 2019 |
| CJ Rendering & Construction Ltd | Construction | 2023 |
| Cjdeliveriess Ltd | Transport & logistics | 2026 |
| CJF Financial Solutions Ltd | Other services | 2023 |
| CJM Commercials Ltd | Wholesale & retail | 2014 |
| CJM Financial Services Ltd | Financial services | 2026 |
| CJS Courier Services Ltd | Transport & logistics | 2025 |
| CK Leisure Limited | Professional & scientific | 2018 |
| Ckbr Property Limited | Administrative & support | 2023 |
| CKS Surfacing Ltd | Construction | 2023 |
| CKT Bakery Ltd | Financial services | 2021 |
| CL B-Connected Ltd | Wholesale & retail | 2015 |
| CL Beet Limited | Health & social care | 2026 |
| CL Groundworks & Civils Ltd | Construction | 2025 |
| Claire Stabler Aesthetics Ltd | Other services | 2024 |
| Claire's Clerical Ltd | Professional & scientific | 2010 |
| Clarity NDT Ltd | Professional & scientific | 2019 |
| Clarke Smith Advisory Ltd | Professional & scientific | 2023 |
| Clarkson Property Investments Ltd | Real estate | 2025 |
| Clarksons Memorials Ltd | Other services | 2013 |
| Clas Haulage Limited | Water & waste | 2017 |
| Classic Engineering Ltd | Professional & scientific | 2024 |
| Classique Home Improvements Ltd | Wholesale & retail | 2006 |
| Clawsius Ltd | Information & communication | 2025 |
| Clay & Sons Limited | Professional & scientific | 2021 |
| Claycraft Construction Limited | Construction | 2006 |
| Clayton 'N' Scotts PIT Stop Limited | Hospitality | 2019 |
| Clayton Hoists Limited | Other services | 2014 |
| CLC Irish Doncaster Ltd | Financial services | 2026 |
| Clean and DRY Specialists Ltd | Administrative & support | 2017 |
| Clean Beet Ltd | Agriculture & fishing | 2023 |
| Clean UP London Limited | Real estate | 2017 |
| Cleana Touch Solutions Ltd | Administrative & support | 2025 |
| Cleanheat Leisure Ltd | Wholesale & retail | 2022 |
| Clear Quality Consulting Limited | Professional & scientific | 2026 |
| Clear Quality Limited | Professional & scientific | 2017 |
| Clear View by Ginova Limited | Wholesale & retail | 2025 |
| Clearview Garden Buildings Ltd | Construction | 2018 |
| Clearview Greenhouses Ltd | Construction | 2018 |
| Clearview Property Inspections Ltd | Administrative & support | 2015 |
| Clement Mews Tenants Association Limited | Households | 2000 |