| Capri Mechanical Services Trustee Limited | Financial services | 2022 |
| Caprice Production Company Limited | Arts & recreation | 2026 |
| Capstone Pharmaco Limited | Health & social care | 2006 |
| Captive Media Technology Limited | Information & communication | 2017 |
| Captured by Polly Ltd | Professional & scientific | 2024 |
| Car Delivery Essex Ltd | Transport & logistics | 2015 |
| Car Kingdom Ltd Ltd | Wholesale & retail | 2018 |
| Car Matcher Ltd | Wholesale & retail | 2024 |
| Car Tracker Service Limited | Wholesale & retail | 2019 |
| Carafran Limited | Households | 1985 |
| Caravan Finder Limited | Information & communication | 2000 |
| Cara’S Canines Ltd | Other services | 2020 |
| Carbel Limited | Construction | 2026 |
| Carberry Contract Services Ltd | Construction | 2006 |
| Carberry Holdings Limited | Administrative & support | 2017 |
| Carberry Investments Limited | Real estate | 2016 |
| Carbon Trade Cars Ltd | Wholesale & retail | 2025 |
| Cardealsessex Ltd | Wholesale & retail | 2026 |
| Cardinal Health Ltd | Health & social care | 2024 |
| Cardinal Lofts Company Limited | Administrative & support | 2003 |
| Care and Support Companions Limited | Health & social care | 2025 |
| Care Free Properties Ltd | Extraterritorial | 2017 |
| Care Lane Services Ltd. | Health & social care | 2022 |
| Care Lifeline Agency Ltd | Administrative & support | 2024 |
| Careclean (Essex) Limited | Administrative & support | 2002 |
| Careoptus Ltd | Health & social care | 2025 |
| CARES360 Ltd | Education | 2026 |
| Carew Close (Chafford Hundred) Management Company Limited | Households | 2001 |
| Cari on Regardless Ltd | Professional & scientific | 2025 |
| Caring Nest Ltd | Health & social care | 2025 |
| Carins Clearout Ltd | Administrative & support | 2020 |
| Carl Shillcock Limited | Other services | 2008 |
| Carlton ST Peter Properties Ltd | Real estate | 2015 |
| Carly Oliver Wealth Management Limited | Professional & scientific | 2024 |
| Carmel Jane Photography Ltd | Professional & scientific | 2013 |
| Carmel Saulbrey Ltd | Real estate | 2019 |
| Carmichael Browns Renewables Ltd | Construction | 2010 |
| Carmichael-Browns Limited | Administrative & support | 2000 |
| Caroline L Kiedish Limited | Administrative & support | 2024 |
| Carpath Limited | Professional & scientific | 2017 |
| Carpati Trading Ltd | Wholesale & retail | 2023 |
| Carpen C Engineering Ltd | Construction | 2015 |
| Carpet Bright UK - Essex Ltd | Administrative & support | 2025 |
| Carpet Care Cleaning Limited | Administrative & support | 2017 |
| Carpex Ltd | Construction | 2025 |
| Carrasco & Carrasco Limited | Hospitality | 2011 |
| Carrera Capital Limited | Financial services | 2016 |
| Carreward Limited | Information & communication | 2021 |
| Carrstone Properties Limited | Real estate | 2010 |
| Carruthers and Hobbs Design Limited | Arts & recreation | 2005 |
| Carter Brickwork Solutions Limited | Construction | 2026 |
| Carter Building Services Limited | Construction | 2013 |
| Carter Property Associates Limited | Real estate | 2017 |
| Carter Resolutions Limited | Information & communication | 2024 |
| Carvion Group Ltd | Wholesale & retail | 2025 |
| Caryatid Investments Limited | Information & communication | 2021 |
| CAS MAX Consulting Ltd | Professional & scientific | 2011 |
| Casa Contemporary Limited | Wholesale & retail | 2024 |
| Casa Redd Ltd | Real estate | 2026 |
| Casa Tinoco Ltd | Health & social care | 2025 |
| Cascelle Contractors Limited | Construction | 2007 |
| Casha Technologies Limited | Information & communication | 2025 |
| Caskaway Management Ltd | Professional & scientific | 2019 |
| Castell Computer and Systems Telecommunications Limited | Information & communication | 1977 |
| Castle & Green Limited | Other services | 2025 |
| Castle Point Contracts Limited | Construction | 2009 |
| Castle Properties (Rayleigh) Limited | Real estate | 1963 |
| Castle Waste Services & Recycling Ltd | Wholesale & retail | 2024 |
| Castro Building Services Ltd | Construction | 2021 |
| Cat Initiatives Ltd | Administrative & support | 2016 |
| Cat Risk Insight Limited | Professional & scientific | 2010 |
| Catalyst 14 Ltd | Administrative & support | 2016 |
| Catchit Laboratories (UK) Limited | Manufacturing | 2014 |
| Category Partners Limited | Hospitality | 2013 |
| Catering Plus Ltd | Hospitality | 2015 |
| Catering Wholesalers Limited | Wholesale & retail | 2010 |
| Catesby Wilson Developments Limited | Construction | 2007 |
| Cathedral Holdings Limited | Financial services | 2000 |
| Cathedral Walk Property FH Limited | Real estate | 2018 |
| Catherine Turner Productions LLP | | 2022 |
| Catify Data Solutions Limited | Construction | 2025 |
| Catify Limited | Construction | 2025 |
| Catkazoo Limited | Information & communication | 2017 |
| Catkom Earthworks Ltd | Construction | 2025 |
| Catsmith Studios Ltd | Arts & recreation | 2024 |
| Catsurveys Ltd | Construction | 2004 |
| Cause and Effects Limited | Information & communication | 2024 |
| Causeway Property Developers Limited | Real estate | 2022 |
| Causeway Worthing Ltd | Construction | 2021 |
| Cavaro Property Limited | Real estate | 2025 |
| Cavea Limited | Professional & scientific | 2019 |
| Cavendish & Co Interiors Ltd | Wholesale & retail | 2019 |
| Cavendish Accountancy Limited | Professional & scientific | 2012 |
| Cavendish Home & Living Ltd | Wholesale & retail | 2019 |
| Cavendish Laboratories Holdings Limited | Financial services | 2022 |
| Cavendish Laboratories Limited | Other services | 1995 |
| Cavendish Silks Limited | Professional & scientific | 2003 |
| Cavetto Limited | Manufacturing | 2025 |
| Cavio (UK) Limited | Professional & scientific | 2000 |
| CAW Property Solutions Ltd | Real estate | 2025 |