| Carna Limited | Extraterritorial | 1959 |
| Caroline Court (1993) Limited | Households | 1993 |
| Carrington Property Investments UK Limited | Real estate | 2021 |
| CAS Mcgee Ltd | Professional & scientific | 2009 |
| Casebond Limited | Real estate | 2009 |
| Casserley Consulting International Ltd. | Professional & scientific | 2020 |
| Castle Bake Ltd | Manufacturing | 2026 |
| Castlekeep Estates Limited | Real estate | 2021 |
| Catalyst Concepts Limited | Professional & scientific | 2013 |
| Cater Crew Limited | Hospitality | 2024 |
| Cathcart Management Company Limited | Households | 1989 |
| Catsoft Ltd | Information & communication | 2018 |
| Caversham North Ltd | Real estate | 2014 |
| Cayliff Investments Limited | Real estate | 2007 |
| CC Commercial Services Limited | Administrative & support | 2023 |
| CCP (Hvac) Limited | Construction | 2014 |
| CCT Admin Ltd | Administrative & support | 2022 |
| CDRS1 Ltd | Extraterritorial | 2015 |
| CDS Sourcing Limited | Wholesale & retail | 2025 |
| Cedar Grove Property Holdings Limited | Real estate | 2025 |
| Cedar Peak Partners Ltd | Professional & scientific | 2025 |
| Cedars Properties (UK) Ltd | Real estate | 2021 |
| Celebrity Media Limited | Professional & scientific | 2019 |
| Celenaisyounique Limited | Professional & scientific | 2016 |
| Celeste Sound Ltd | Administrative & support | 2022 |
| Cemco Trading Limited | Hospitality | 2023 |
| Censual Property Ltd | Real estate | 2023 |
| Centauride Investments Ltd | Administrative & support | 2018 |
| Central AV Limited | Information & communication | 2003 |
| Central Property Advisors Limited | Real estate | 2020 |
| Centre for Biodynamic Psychotherapy Ltd | Extraterritorial | 2014 |
| Centre Stage Strategy Ltd | Information & communication | 2021 |
| CEO Ventures Property Limited | Real estate | 2025 |
| Cepy Logistics Ltd | Transport & logistics | 2025 |
| CES Investments Limited | Professional & scientific | 2009 |
| CFS Enfield Limited | Extraterritorial | 2011 |
| CG Heating Group Limited | Construction | 2019 |
| CG Plus Properties Ltd | Real estate | 2013 |
| CGM Design Ltd | Professional & scientific | 2019 |
| Chadson Properties Ltd | Real estate | 2021 |
| Chair Mats Limited | Wholesale & retail | 2012 |
| Chalcots Estate Limited | Real estate | 2004 |
| Chambers Transport Limited | Transport & logistics | 2018 |
| Channel Twelve Ltd | Arts & recreation | 2020 |
| Chanterelle Ltd | Real estate | 2019 |
| Chapman & Pitt Limited | Construction | 2004 |
| Charles Skehan Construction Ltd | Administrative & support | 2016 |
| Charles Winter Interiors Limited | Construction | 2017 |
| Charlietully Limited | Construction | 2025 |
| Charlwood Street Estates Limited | Real estate | 2014 |
| Charm Ventures Ltd | Real estate | 2019 |
| Chartercourt Limited | Professional & scientific | 1969 |
| Chartercourt Media Limited | Professional & scientific | 2025 |
| Chartmay Limited | Arts & recreation | 1980 |
| Chase Roofing Limited | Construction | 2025 |
| Chatrbx Ltd | Extraterritorial | 2015 |
| Chaucer Road Management Company Limited | Households | 2021 |
| Chegmac Property Co. Limited | Professional & scientific | 1964 |
| Chelico Holdings Ltd | Real estate | 2019 |
| Chelsea Clinic Ltd | Administrative & support | 2016 |
| Chequers Mead Holdco Limited | Real estate | 2023 |
| Chequers Mead Propco Limited | Real estate | 2022 |
| Chester Auto Exclusive Limited | Wholesale & retail | 2023 |
| CHF Retail Limited | Wholesale & retail | 2012 |
| Chimera Energy Ltd | Professional & scientific | 2020 |
| China Style Foods Limited | Hospitality | 2022 |
| China Style Takeaway Limited | Hospitality | 2025 |
| Chine Home & Estates Limited | Real estate | 2021 |
| Chris O Film Limited | Information & communication | 2015 |
| Chris's Barber Shop Limited | Other services | 2009 |
| Chrisandmell Limited | Real estate | 2007 |
| Christian J Andrews Limited | Real estate | 2018 |
| Christianna's Creations Limited | Wholesale & retail | 2017 |
| Chronicle Publishing Ltd | Information & communication | 2023 |
| Chrysos Investments Ltd | Real estate | 2022 |
| Church Close Freehold Ltd | Extraterritorial | 1998 |
| Cibo Groceries Limited | Construction | 1974 |
| Cilento Limited | Wholesale & retail | 2012 |
| Ciniviz&Malik Ltd | Real estate | 2025 |
| Circa Care Limited | Health & social care | 2006 |
| Circular Earth Ltd | Professional & scientific | 2022 |
| Circus of Gorillas Ltd | Administrative & support | 2023 |
| Citihome Glasgow Holdings Ltd | Hospitality | 2018 |
| Citrine Management Ltd | Households | 2020 |
| Citronic Ltd | Administrative & support | 2016 |
| City Clinic of Osteopathic Medicine Limited | Health & social care | 2012 |
| City Glaze Ltd | Construction | 2026 |
| City Secretarial Services Limited | Professional & scientific | 2002 |
| Citybay Estates Limited | Real estate | 2007 |
| Citybay Investment Limited | Real estate | 2007 |
| Citybay Limited | Real estate | 1996 |
| Citybay Management Limited | Real estate | 2007 |
| Citybay Property Limited | Real estate | 2007 |
| Citywide Electrical Services Limited | Construction | 2003 |
| CJ Ackroyds Roofing & Property Maintenance Limited | Construction | 2022 |
| CJ Knight Holdings Ltd | Financial services | 2018 |
| CJ Plastering and Properties Ltd | Construction | 2017 |
| Cjbks Ltd | Information & communication | 2019 |
| CJE Contractors Ltd | Construction | 2026 |
| Cjts Properties Limited | Real estate | 2023 |