| Chelmsford Brew Co Bars Limited | Hospitality | 2022 |
| Chelmsford Flooring Limited | Construction | 2019 |
| Chelsea Brickwork Ltd | Construction | 2025 |
| Chelsea Watch Company Ltd | Wholesale & retail | 2021 |
| Chequers Court Limited | Households | 1989 |
| Cherry Tree Court (London E18) Management Company Limited | Households | 1996 |
| Cherry Tree Management & Consultancy Services Limited | Administrative & support | 2003 |
| Cheshunt Lakeside Management Company Limited | Households | 2020 |
| Chester Real Estate Limited | Administrative & support | 2008 |
| Chicago Grill Catering Company Limited | Hospitality | 2023 |
| Chicago Grill Fast Food Service Limited | Hospitality | 2024 |
| Chicken & Sprout Limited | Real estate | 2025 |
| Child Autism & Development Limited | Health & social care | 2022 |
| Chiltern Court Properties Limited | Construction | 2017 |
| Chingford Mount PUB Ltd | Hospitality | 2019 |
| Chisomo Trades Ltd | Financial services | 2026 |
| Chit Chat Cafe Limited | Hospitality | 2025 |
| Chobham Farm Zone 3D1 Residents Management Company Limited | Households | 2022 |
| Choice Developments Ltd | Construction | 2018 |
| Choice Interior Solutions Ltd | Construction | 2012 |
| Choice Staffing Ltd | Administrative & support | 2018 |
| Choicetime Limited | Construction | 2000 |
| Chris Clark Electrical Services Ltd | Construction | 2026 |
| Chris Interiors Limited | Construction | 2009 |
| Christina Meyer Property Limited | Real estate | 2013 |
| Chronofinder Ltd | Administrative & support | 2017 |
| Chrysanth Consulting Ltd | Real estate | 2018 |
| CHS Investment Properties Limited | Real estate | 2015 |
| CHT Ventures Limited | Administrative & support | 2019 |
| Church Hill Loughton Management Company Limited | Administrative & support | 2014 |
| Church Lane 1 Limited | Professional & scientific | 2020 |
| Churchill Business Development and Property Development Limited | Construction | 2026 |
| Churchsmith Ltd | Wholesale & retail | 2019 |
| Cigma Construction Ltd | Construction | 2018 |
| Cimple Solutions Limited | Information & communication | 2020 |
| CIP Builders Ltd | Construction | 2025 |
| Citi CAP Trading Limited | Real estate | 2024 |
| Citihold Limited | Real estate | 2021 |
| Citivest Limited | Construction | 2021 |
| Citivest Properties Limited | Construction | 2021 |
| Citivest Shirley Limited | Construction | 2022 |
| Citivest TL Limited | Real estate | 2024 |
| Citivest Trading Limited | Real estate | 2024 |
| Citrine 888 Holdings Limited | Hospitality | 2025 |
| Citrus (Pbishops) Durham Ltd | Real estate | 2022 |
| City Accountancy & Consultancy Services Limited | Professional & scientific | 2015 |
| City Seven Group Ltd | Construction | 2020 |
| City VIP Chauffeurs Limited | Transport & logistics | 2019 |
| Citygate Surveyors Ltd | Professional & scientific | 2012 |
| Civil Consultancy Limited | Professional & scientific | 2020 |
| CJ25 Promotions and Property Limited | Information & communication | 2012 |
| CJR Contracts Ltd | Construction | 2017 |
| CK Private Limited | Professional & scientific | 2024 |
| CKP Asset Management Limited | Professional & scientific | 2015 |
| CL Brands Limited | Construction | 2017 |
| Claire Capital Partners Limited | Financial services | 2025 |
| Claire Properties Ltd | Real estate | 2019 |
| Claire Truss Ltd | Health & social care | 2024 |
| Clarendon Road Developments Limited | Real estate | 2016 |
| Clarity Medical Limited | Other services | 2020 |
| Clark Baker & SON Limited | Arts & recreation | 2005 |
| Clarke Family Consulting Ltd | Information & communication | 2020 |
| Clarke Family Holdings Ltd | Real estate | 2019 |
| Claro Jewels Limited | Wholesale & retail | 2018 |
| Clayhall Executive Cars Limited | Transport & logistics | 2007 |
| Claymen Properties Limited | Real estate | 2024 |
| Clbr Limited | Real estate | 2024 |
| CLC Facilities Limited | Construction | 2002 |
| Clean Nation Ltd | Water & waste | 2010 |
| Cleaning Support & Service Ltd | Administrative & support | 2023 |
| Cleaning UK Limited | Professional & scientific | 2006 |
| Cleanwell 21 Ltd | Administrative & support | 2016 |
| Cleanwell London Limited | Administrative & support | 2015 |
| Clear Architects Limited | Professional & scientific | 2005 |
| Clearly One Ltd | Manufacturing | 2026 |
| Cleethorpes PJ Limited | Hospitality | 2016 |
| Cleori Customs Ltd | Transport & logistics | 2026 |
| Clerkenwell Design Week Limited | Administrative & support | 2009 |
| Clermont Facilities & Building Services Limited | Construction | 2024 |
| Clermont Group Recruitment Ltd | Administrative & support | 2021 |
| Clever Cleaning Solutions Ltd | Other services | 2014 |
| Client Support Services (UK) Limited | Other services | 2007 |
| Cliff Adams Management Limited | Arts & recreation | 1960 |
| Cliff Hill Freehold Limited | Households | 2018 |
| Cliffgold Limited | Construction | 2001 |
| Cliffhanger London Ltd | Arts & recreation | 2026 |
| Clifton Hill Investments Limited | Administrative & support | 2017 |
| Clinrt Limited | Information & communication | 2023 |
| CLJ Flooring Specialists Limited | Construction | 2019 |
| Clockwork Mechanical Services Ltd | Wholesale & retail | 2016 |
| Clothes Encounters Limited | | 1979 |
| Clothing Care DC Ltd | Other services | 2020 |
| Cloud Code Ltd | Extraterritorial | 2010 |
| CLOUD9 Records Limited | Information & communication | 2011 |
| Clouddigit Ltd | Information & communication | 2019 |
| Cloudfusion Consulting Limited | Information & communication | 2025 |
| Clover Apps Limited | Information & communication | 2020 |
| Cluster Technologies Ltd | Wholesale & retail | 2025 |
| CM Cleaning Support Ltd | Administrative & support | 2022 |
| Cmgp Trading Ltd | Wholesale & retail | 2020 |