| CD Mgmt Ltd | Hospitality | 2025 |
| CDA Technology Limited | Wholesale & retail | 2009 |
| CE Financial Limited | Professional & scientific | 2021 |
| Cebt Consultancy Limited | Arts & recreation | 2002 |
| Cedus Limited | Information & communication | 2012 |
| Celebrate Good Times Ltd | Administrative & support | 2014 |
| Celo Services Limited | Construction | 2017 |
| Central Maintenance and Management Ltd | Construction | 2013 |
| Central Medical Rooms Ltd | Other services | 2024 |
| Central Mortgage Packaging Limited | Information & communication | 2007 |
| Central Mortgages (Essex) Ltd | Administrative & support | 2003 |
| Central Mortgages Limited | Administrative & support | 2015 |
| Centripetal Consulting Services Limited | Information & communication | 2010 |
| Certis International Limited | Professional & scientific | 2001 |
| Certo Construction ( London ) Ltd | Construction | 2018 |
| Certus IP Solutions Ltd | Professional & scientific | 2025 |
| CFB Education Consultancy Ltd. | Education | 2021 |
| CGD Contracting Services Ltd | Construction | 2014 |
| Cgdf Property Limited | Real estate | 2015 |
| Cgrb Limited | Construction | 2011 |
| Cguk Organisation Ltd | Education | 2019 |
| Chad Higgins Productions Limited | Real estate | 2021 |
| Chafford Tots to Teens Childcare Services Ltd | Health & social care | 2014 |
| Challoner Wealth Management Limited | Professional & scientific | 2018 |
| Chamberlain Plant Hire Limited | Transport & logistics | 1981 |
| Chambres Estates Ltd | Real estate | 2010 |
| Champain Limited | Extraterritorial | 2003 |
| Champions Betting Limited | Arts & recreation | 2018 |
| Chandlers Chase(Rose Lane) Billericay Ltd | Households | 2011 |
| Change Right Group Ltd | Professional & scientific | 2022 |
| Chantry Design & Build Ltd | Construction | 2025 |
| Chapel Court Property Limited | Real estate | 2026 |
| Chapel Street Kitchen Limited | Hospitality | 2019 |
| Chappel Valley Ltd | Hospitality | 2022 |
| Charwood Mews Management Company Limited | Households | 2019 |
| Chase & Co Advertising Ltd | Professional & scientific | 2008 |
| Chase Court Residents' Management Limited | Households | 1994 |
| Chase Distribution Limited | Wholesale & retail | 2011 |
| Chats Limited | Transport & logistics | 1987 |
| Chelmer Wealth Management Ltd | Professional & scientific | 2023 |
| Chelmsford Construction Ltd | Construction | 2024 |
| Chelsea Portfolio 2022 Ltd | Real estate | 2022 |
| Chelsea Portfolio Limited | Real estate | 1996 |
| Chenalfame Limited | Administrative & support | 1982 |
| Cherish Jane Beauty Limited | Other services | 2011 |
| Cherry Inn Limited | Hospitality | 2021 |
| Cherry ROW Limited | Real estate | 2021 |
| Chestnut House Investments Ltd | Professional & scientific | 2014 |
| CHG Records Limited | Administrative & support | 2023 |
| Chimes Home & Garden Ltd | Manufacturing | 2019 |
| Chip Events Limited | Hospitality | 2024 |
| Chirohub Limited | Administrative & support | 2023 |
| Chmj Ltd | Professional & scientific | 2014 |
| Choice Nursery Recruitment Ltd | Administrative & support | 2024 |
| Choice Recruitment Services Ltd | Administrative & support | 2017 |
| Chris Brown Management Ltd | Other services | 2018 |
| Chris Clarkson Consultancy Limited | Information & communication | 2012 |
| Chris Dekker Media Ltd | Other services | 2020 |
| Chris Nunn Golf Limited | Education | 2020 |
| Chris's DIY Merrington Ltd | Wholesale & retail | 1998 |
| Christchurch Property Holdings Ltd | Real estate | 2016 |
| Christian Growth Centre Basildon | Other services | 2010 |
| Christopher Anthony Developments Limited | Construction | 2025 |
| Christopher Anthony Interiors Limited | Construction | 2018 |
| Churchill Robins Limited | Financial services | 2016 |
| Cilligan Consulting Ltd | Professional & scientific | 2019 |
| Cipic Ltd | Transport & logistics | 2021 |
| Circles ALT ED C.I.C. | Education | 2014 |
| Citrus Property Group Limited | Real estate | 2025 |
| City Commodity Brokers Limited | Professional & scientific | 2014 |
| City Electrics London Limited | Construction | 2007 |
| Civicare East Ltd | Administrative & support | 2000 |
| CL Collaborative Ltd | Wholesale & retail | 2025 |
| Claire Bannister Coaching Ltd | Professional & scientific | 2024 |
| Claire Louise Hill Ltd | Administrative & support | 2024 |
| Clan Ecolectrical Limited | Construction | 2010 |
| Clarion Advisory London Ltd | Administrative & support | 2026 |
| Clarity in Marketing Limited | Administrative & support | 2008 |
| Clark Designs Limited | Administrative & support | 2005 |
| Clarke Capital Holdings Limited | Administrative & support | 2017 |
| Clarkesvilla Limited | Professional & scientific | 2019 |
| Clarkson Sales Consulting Ltd | Financial services | 2024 |
| Clarky Limited | Financial services | 2025 |
| Clavin-It Limited | Information & communication | 2013 |
| Clean and Serene Ltd | Water & waste | 2013 |
| Clear IFA Limited | Financial services | 2004 |
| Clear Surface Co Limited | Administrative & support | 2026 |
| Clearwater Automotive Limited | Real estate | 2009 |
| Clearwater Projects (Commercial) Limited | Construction | 2017 |
| Clearwater Projects Limited | Construction | 2006 |
| Clever Lili Limited | Information & communication | 2017 |
| Click Office Supplies Limited | Wholesale & retail | 2018 |
| Cliff's Joinery & Fitting Limited | Construction | 2021 |
| Clinical Investigations Ltd | Professional & scientific | 2023 |
| CLM Homes Ltd | Real estate | 2023 |
| Close Brothers Building Services Limited | Extraterritorial | 2017 |
| Close Brothers Environmental Services Limited | Extraterritorial | 2017 |
| Close Brothers Labour Supply Limited | Extraterritorial | 2017 |
| Close Brothers Plant Hire Limited | Extraterritorial | 2017 |
| Close Brothers Reactive Maintenance Limited | Extraterritorial | 2017 |