| Charlbury Property Management Company Limited | Households | 2018 |
| Charles MAE Global Limited | Wholesale & retail | 2025 |
| Charlie Babb Hair Limited | Other services | 2019 |
| Charlies Unisex Salon Limited | Other services | 2011 |
| Charmma Healthcare Limited | Health & social care | 2024 |
| Chartex Concepts Ltd. | Professional & scientific | 2020 |
| Chartwell Close Croydon Freehold Company Limited | Households | 1996 |
| Chartwell Close Management Company Limited | Households | 1991 |
| Chase Project Consultancy Limited | Professional & scientific | 2019 |
| Chatsworth Place (Impington) Management Company Limited | Real estate | 2020 |
| Chatteris Court RTM Company Limited | Households | 2010 |
| Chauffeur DE Luxe Ltd | Transport & logistics | 2023 |
| Chayil Health Limited | Health & social care | 2025 |
| Cheap Training Ltd | Education | 2020 |
| Chebac Ltd | Transport & logistics | 2020 |
| Chedanu Limited | Health & social care | 2025 |
| Chedas Limited | Health & social care | 2018 |
| Chekas Limited | Real estate | 2012 |
| Chelsea VIP Limited | Transport & logistics | 2021 |
| Chequers Court (Langley) Management Limited | Households | 1990 |
| Chequers Propco Ltd | Real estate | 2024 |
| Cherished Chapters Limited | Administrative & support | 2019 |
| Cherishing Moments Limited | Information & communication | 2023 |
| Cherix Trans Ltd | Transport & logistics | 2023 |
| Cherry Pascal Limited | Hospitality | 2021 |
| Cherry Picker Ltd | Real estate | 2016 |
| Cheshunt Motor Company Limited(The) | Wholesale & retail | 1983 |
| Chestnuts (Puckeridge) Management Company Limited | Administrative & support | 2018 |
| Chez Limited | Health & social care | 2026 |
| CHI YU Limited | Arts & recreation | 2008 |
| Chi-Fumad Limited | Administrative & support | 2015 |
| Chibili Health Limited | Health & social care | 2021 |
| Chichi Onyekwum Limited | Health & social care | 2026 |
| Chicmed Limited | Health & social care | 2023 |
| Chief Cleaning Solutions Ltd | Administrative & support | 2024 |
| Chiege's Limited | Wholesale & retail | 2020 |
| Chilavee Digital Limited | Information & communication | 2025 |
| Chiltern Rise Management Company Limited | Households | 2013 |
| Chime Tech Limited | Administrative & support | 2018 |
| Chimes Group Ltd | Hospitality | 2017 |
| Chingford Home Improvements Ltd | Construction | 2024 |
| Chinke Medical Ltd | Health & social care | 2021 |
| Chiomaultra Company Limited | Health & social care | 2022 |
| Chip Technology Limited | Information & communication | 1978 |
| Chipeng International Data Corporation Limited | Manufacturing | 2024 |
| Chiswick & Cedar Properties Ltd | Real estate | 2008 |
| Chivin Estates & Properties UK (Cepl UK) Ltd | Real estate | 2024 |
| Chloe's UK Salon Limited | Other services | 2022 |
| Chocdoc Limited | Health & social care | 2025 |
| Chomex Medicare and Supplies Ltd | Health & social care | 2022 |
| Choose Smart Ltd | Wholesale & retail | 2024 |
| Chop Trans Limited | Transport & logistics | 2016 |
| Choppy CUT Academy Limited | Education | 2017 |
| Choppy Cuts Limited | Other services | 2013 |
| Chordal Green Group Ltd | Financial services | 2024 |
| Chordal Green Ltd | Manufacturing | 2006 |
| Chosen Vessel Creations Ltd | Information & communication | 2023 |
| Chris Build Limited | Construction | 2024 |
| Chris Tate Legal Services Ltd | Professional & scientific | 2013 |
| Chrisfeli Limited | Health & social care | 2022 |
| Christ Fellowship Centre Ltd | Other services | 2021 |
| Christ Govern Church Revival Ministry | Other services | 2025 |
| Christodel Legal Consulting Ltd | Professional & scientific | 2017 |
| Christopher Frostick Flowers Ltd | Wholesale & retail | 2025 |
| Chriswiniqua Care Ltd | Health & social care | 2022 |
| CHS Legal Limited | Professional & scientific | 2026 |
| Church Langley Community Association | Health & social care | 1995 |
| Church's of Epping Limited | Construction | 1957 |
| Churchgate Trading Ltd | Wholesale & retail | 2024 |
| Cian London Ltd | Construction | 2021 |
| Cics Security Services UK Limited | Administrative & support | 2025 |
| CID Civil & Surfacing Limited | Construction | 2020 |
| CID Properties Limited | Real estate | 2024 |
| Ciessey Sons and Daughters Ltd | Manufacturing | 2025 |
| Cinderella Cleaning UK Limited | Administrative & support | 2022 |
| Cindy Ventures Ltd | Health & social care | 2015 |
| Cineglamping Ltd | Information & communication | 2020 |
| Circle Line Limited | Manufacturing | 2003 |
| Ciso Advisory Group Ltd | Information & communication | 2025 |
| Citiglen Limited | Wholesale & retail | 1999 |
| Citiscan Services Limited | Health & social care | 2025 |
| City and Countrywide Limited | Real estate | 2022 |
| City Rubbish Clearance Ltd | Water & waste | 2025 |
| City SA Limited | Wholesale & retail | 2019 |
| CJ Financial Limited | Real estate | 2011 |
| Cjar Medical Ltd | Health & social care | 2026 |
| Cjexpress Services Limited | Transport & logistics | 2024 |
| CJL Climate Services Limited | Construction | 2023 |
| CJR Property Management Ltd | Real estate | 2021 |
| CJS Dent Limited | Health & social care | 2017 |
| Cjsmartrepair Ltd | Wholesale & retail | 2025 |
| CK Air Conditioning Ltd | Construction | 2022 |
| CKI Tech Limited | Information & communication | 2018 |
| CKK Lighting Limited | Wholesale & retail | 2025 |
| CL Facilities Solutions Ltd | Administrative & support | 2025 |
| Claira Limited | Wholesale & retail | 2026 |
| Claire Court (Cheshunt) Limited | Households | 1984 |
| Clara Medicare Ltd | Health & social care | 2014 |
| Clare Lodge RTM Company Limited | Households | 2015 |
| Clare Waller Pubs Ltd | Hospitality | 2025 |