| Cool Data Limited | Information & communication | 2025 |
| Coolflo Airconditioning Limited | Construction | 2002 |
| Coombe Express Ltd | Wholesale & retail | 2019 |
| Cooo Limited | Real estate | 2022 |
| Cooper & Potts Flooring Services Limited | Construction | 1997 |
| Cooper and Co. (Sutton) Limited | Wholesale & retail | 2012 |
| Cordoba Solutions Ltd | Other services | 2026 |
| Coreautomatrix QA Consulting Ltd | Information & communication | 2026 |
| Corenet Tech London Limited | Information & communication | 2024 |
| Coriander Court Management Limited | Households | 1978 |
| Cornerstone Sports Ltd | Arts & recreation | 2025 |
| Cornfield Terrace Management Limited | Real estate | 2017 |
| Cornish Roofing Contractors Ltd | Construction | 2025 |
| Corporate Asset Risk Management Ltd | Financial services | 2025 |
| Corvus Property Limited | Real estate | 2010 |
| Cosden Trading Ltd | Construction | 2017 |
| Cosmic Comics Limited | Wholesale & retail | 2025 |
| Cost Savers OFF Licence Limited | Wholesale & retail | 2016 |
| Costaconsult Ltd | Health & social care | 2017 |
| Cotswold Cigars Ltd | Wholesale & retail | 2025 |
| Cotton Harbour Limited | Hospitality | 2009 |
| Cottonwood Partners Limited | Professional & scientific | 2012 |
| Country Wide Holdings Ltd | Real estate | 2016 |
| County Technical Solutions Ltd | Construction | 2018 |
| Courtangle Limited | Professional & scientific | 1997 |
| Cove Retreat Limited | Hospitality | 2018 |
| Cowley Asset Holdings Ltd | Financial services | 2026 |
| Cowley Estates Ltd | Real estate | 2026 |
| Cowley Group Holdings Ltd | Financial services | 2026 |
| Coyle's Little Class Company Limited | Education | 2026 |
| Coyote Theatre Ltd | Arts & recreation | 2024 |
| Coyote Theatre TOO Ltd | Arts & recreation | 2025 |
| Cozzy Lounge Ltd | Hospitality | 2022 |
| CP & PP Property Limited | Real estate | 2021 |
| CPJ Group Limited | Financial services | 2019 |
| CPM Associates Limited | Professional & scientific | 2003 |
| CR13 Padel Limited | Arts & recreation | 2024 |
| Craden Moore Solicitors Ltd | Professional & scientific | 2019 |
| Craft Communications Limited | Professional & scientific | 2013 |
| Crafted Conversions Ltd | Construction | 2026 |
| Crafted Networks Ltd | Information & communication | 2017 |
| Craig Johnny Michael Ltd | Hospitality | 2025 |
| Cramer Acupuncture Ltd | Health & social care | 2024 |
| Cramhurst Freehold Limited | Households | 1996 |
| Cramhurst Management Company Limited | Households | 1976 |
| Cranford Court Limited | Households | 2019 |
| Crawley Chiropractic Clinic Ltd | Health & social care | 2020 |
| CRE 001 Limited | Real estate | 2023 |
| CRE8TIVE Contractors Ltd | Construction | 2019 |
| Create & Optimise Ltd | Professional & scientific | 2020 |
| Create IT Recruitment Limited | Administrative & support | 2019 |
| Creative H & B Limited | Other services | 2016 |
| Creative Hair Design Ltd | Other services | 2001 |
| Creative Payroll Solutions Ltd | Administrative & support | 2010 |
| Creative Space Belmont Ltd | Arts & recreation | 2025 |
| Creativecrest Consulting Limited | Information & communication | 2012 |
| Cremation INK Limited | Other services | 2018 |
| Crescent Grocers Ltd | Wholesale & retail | 2022 |
| Crescent Projects Limited | Professional & scientific | 2004 |
| Cressingham Grove Freehold Company Limited | Households | 2015 |
| Crest Health Group Limited | Health & social care | 2022 |
| Cricomm Limited | Information & communication | 2013 |
| Cripes It's Crepes Limited | Hospitality | 2019 |
| Cristiano Lovatelli Ravarino Ltd | Other services | 2016 |
| Cristobel Limited | Real estate | 2013 |
| Critical Friend Consulting Ltd | Professional & scientific | 2023 |
| Critical HIT Energy Limited | Wholesale & retail | 2024 |
| Criticalarc Ltd | Information & communication | 2013 |
| Critzo Limited | Information & communication | 2024 |
| CRM Develop to Live Ltd | Information & communication | 2018 |
| Crob-Holding Ltd | Manufacturing | 2023 |
| Cromer Mansions (Cheam Road, Sutton) Management Limited | Households | 1976 |
| Cross Asset Solutions Limited | Information & communication | 2023 |
| Crossfire Ltd | Professional & scientific | 2014 |
| Crosstc Limited | Other services | 2006 |
| Crossway Classic Cars Ltd | Wholesale & retail | 2008 |
| Crown Developers Ltd | Construction | 2023 |
| Crown Elite Group Ltd | Transport & logistics | 2026 |
| Crown Mead Thatcham Ltd | Hospitality | 2019 |
| Crown Payroll Limited | Professional & scientific | 2022 |
| Croxsons Ltd. | Wholesale & retail | 2009 |
| Croydon Chinese School Ltd | Education | 2025 |
| Croydon Supplies Limited | Wholesale & retail | 2019 |
| Crunch Bite Ltd | Wholesale & retail | 2025 |
| Crystal Nails and Beauty (Sutton) Ltd | Other services | 2020 |
| CS Maids Company Limited | Administrative & support | 2025 |
| CS Militaria Ltd | Wholesale & retail | 2015 |
| CS Red Limited | Real estate | 2021 |
| Csbf Enterprises Limited | Administrative & support | 1995 |
| CSS Paving Design Limited | Construction | 2018 |
| CU Plumbing Ltd | Construction | 2012 |
| Cuarto Capital Partners Limited | Real estate | 2018 |
| Cuarto Consultants Limited | Real estate | 2011 |
| Cuarto Group Limited | Wholesale & retail | 2017 |
| Cuarto Projects Design & Build Ltd | Construction | 2014 |
| Cubcosi Limited | Wholesale & retail | 2021 |
| Cuckfield Road Limited | Real estate | 2018 |
| Cumnor House Limited | Households | 1999 |
| CUP and Crumble Ltd | Hospitality | 2025 |
| Cuppa Coffee Cafe Ltd | Hospitality | 2026 |