| Cheviot Construction Ltd | Construction | 2014 |
| Chic Coffee Ltd | Manufacturing | 2019 |
| Chilli Willy People Ltd | Agriculture & fishing | 2025 |
| Chiltern Delay Analysis Limited | Construction | 2022 |
| Chinese Massage and Herbal Remedies Ltd | Health & social care | 2017 |
| Chislehurst and Sidcup Grammar School | Education | 2011 |
| Chislehurst Barbers Limited | Other services | 2018 |
| Chloames LLP | | 2024 |
| Chloe Marks Ltd | Administrative & support | 2025 |
| Chosen Housing Limited | Real estate | 2024 |
| Chris Cooper Investments Limited | Real estate | 2021 |
| Chris Moreton Consultancy Services Limited | Professional & scientific | 2024 |
| Chris Vincent Cleaning Services Limited | Administrative & support | 2013 |
| Chris Yates Parking Associates Limited | Administrative & support | 1999 |
| Chrisalis Refurbishment Limited | Construction | 2007 |
| Christchurch Electrical Solutions Limited | Construction | 2017 |
| Christiana Wilkins Interior Design Limited | Professional & scientific | 2026 |
| Christine Scally Designs and Solutions Limited | Administrative & support | 2009 |
| Christopher James Limited | Construction | 2014 |
| Christopher Russell LLP | | 2007 |
| Christos Commercials Ltd | Wholesale & retail | 2018 |
| Chroma Contracts Limited | Administrative & support | 2016 |
| CHS Transport Ltd | Administrative & support | 2024 |
| CHT Property Limited | Information & communication | 2019 |
| Chubai Limited | Real estate | 2026 |
| Chumbera Hill Services Limited | Households | 2011 |
| Church Mews Dunton Green Management Company Limited | Households | 2021 |
| Cicero Trading Limited | Hospitality | 2007 |
| Cimen Properties Limited | Real estate | 2023 |
| Cinnamon Limited | Hospitality | 2014 |
| City & West END Paper Ltd | Administrative & support | 2000 |
| City Ergo Ltd | Extraterritorial | 2016 |
| City Executive Cars Ltd | Transport & logistics | 2011 |
| City Hotel Borough Limited | Hospitality | 2018 |
| City Pads London Ltd | Hospitality | 2017 |
| City Project Management Ltd | Professional & scientific | 2012 |
| City Transportation Solutions Limited | Professional & scientific | 2016 |
| Civicon Ltd | Construction | 2023 |
| Ciél Bleu Collective Ltd | Financial services | 2024 |
| CJ London Group Limited | Hospitality | 2019 |
| CJ Love Group Ltd | Financial services | 2020 |
| CK Stone and Restoration Limited | Construction | 2015 |
| CK West Ltd | Construction | 2019 |
| CKC Capital Limited | Real estate | 2020 |
| CKE Services Limited | Manufacturing | 2024 |
| CKK Family Limited | Real estate | 2023 |
| CKT Property Limited | Real estate | 2020 |
| Claims Consultants (UK) Limited | Extraterritorial | 2022 |
| Claire Rowland Associates Ltd | Information & communication | 2013 |
| Clarcad Limited | Professional & scientific | 2018 |
| Clarity Technology Limited | Information & communication | 2019 |
| Clark Assessment Services Ltd | Professional & scientific | 2024 |
| Clark GAS Services Ltd | Construction | 2026 |
| Clark SS Ltd | Administrative & support | 2023 |
| Clark, Davis and Co. Limited | Real estate | 1953 |
| Classic Edition Ltd | Wholesale & retail | 2024 |
| Claude Shannon Limited | Professional & scientific | 1997 |
| Cleaner Greener Safer Happier Ltd | Professional & scientific | 2012 |
| Cleantime Limited | Administrative & support | 1980 |
| Clear ROD Drainage Solutions Ltd | Administrative & support | 2013 |
| Clear Route Couriers Limited | Transport & logistics | 2020 |
| Clearways Business Estate Management Limited | Households | 2017 |
| Clearways Industrial Estate Limited | Real estate | 2016 |
| Cleary Utilities Limited | Administrative & support | 2020 |
| Cleverbox Elevators Ltd | Professional & scientific | 2025 |
| Cliff Wood Consultancy Limited | Professional & scientific | 2009 |
| Cliffords Home Improvements Ltd | Construction | 2024 |
| Climair UK Ltd | Wholesale & retail | 2005 |
| Cliser IT Solutions Limited | Information & communication | 2018 |
| CLM Fire Protection Limited | Construction | 2019 |
| CLM Fire Safety Limited | Construction | 2019 |
| Closeup Promotions Limited | Information & communication | 2017 |
| Clotilde Boquet Limited | Real estate | 2023 |
| Cloud Health Ltd | Health & social care | 2013 |
| Cloud Red Property Management Limited | Information & communication | 2017 |
| Cloudflex Ltd | Information & communication | 2016 |
| Clover Auto Services Ltd | Wholesale & retail | 2024 |
| Clover Cafe Vending Services Ltd | Wholesale & retail | 2020 |
| Clover Car Services Limited | Transport & logistics | 2013 |
| Clover Clobber Limited | Wholesale & retail | 2022 |
| Clover Developments Services Ltd | Real estate | 2023 |
| Clover United Ltd | Financial services | 2025 |
| CLR Services London Ltd | Construction | 2022 |
| Cluster 43 Limited | Professional & scientific | 2017 |
| CMB Management Services Limited | Construction | 2000 |
| Cmcm UK Limited | Professional & scientific | 2024 |
| CMO Waste Clearance Limited | Water & waste | 2025 |
| Cmsd Building Services Ltd | Construction | 2020 |
| Cmta Limited | Administrative & support | 2021 |
| Cmtk Ltd | Information & communication | 2017 |
| Cmyk Software Limited | Information & communication | 2025 |
| Coachability Group Limited | Education | 2021 |
| Cobham Close Management Company Limited | Households | 1991 |
| Coborn Ltd | Professional & scientific | 2017 |
| Cocada Fresco (UK) Limited | Manufacturing | 2009 |
| Cocina Argentina Limited | Administrative & support | 2015 |
| Coco’S Dog Grooming Studio Limited | Administrative & support | 2026 |
| Code Kids EDU Limited | Education | 2019 |
| Code Kids Robotics Limited | Education | 2016 |
| Codekids-Bexley Limited | Education | 2025 |