| Broadway Electrical (Essex) Ltd | Construction | 2022 |
| Brockley Court Ltd | Households | 2017 |
| Brooke Air Diffusion Limited | Manufacturing | 1961 |
| Brooke Air Holdings Limited | Extraterritorial | 1999 |
| Brookeline Autoparts Limited | Wholesale & retail | 2022 |
| Brown & Geeson Limited | Wholesale & retail | 1991 |
| Brown & White Dunmow Ltd | Health & social care | 2021 |
| Brown & White Sudbury Ltd | Other services | 2025 |
| Brown & White Tanning Limited | Other services | 2024 |
| Brown Brothers Holdings Limited | Administrative & support | 2017 |
| Browned OFF Tanning Studio Limited | Wholesale & retail | 2025 |
| BRS Plumbing and Heating Ltd | Construction | 2022 |
| Brumby Trading Limited | Administrative & support | 2013 |
| Brunswick Court Maintenance Limited | Hospitality | 1958 |
| BSG Electrical Services Limited | Construction | 2016 |
| Bstkm Services Limited | Professional & scientific | 2015 |
| BSV Foods Ltd | Hospitality | 2025 |
| BT Reseau Limited | Information & communication | 2010 |
| Bubly Bathrooms Limited | Wholesale & retail | 2023 |
| Buckley Construction Ltd | Construction | 2020 |
| Bugley Ltd | Wholesale & retail | 2005 |
| Build 71 Ltd | Construction | 2019 |
| Build United Ltd | Real estate | 2021 |
| Bullivant Wealth Management Ltd | Financial services | 2020 |
| Burgess Plumbing Limited | Construction | 2022 |
| Burnbet Ltd | Wholesale & retail | 2026 |
| Burr Property Developments Ltd | Construction | 2026 |
| Burton Lodge Racing Ltd | Arts & recreation | 2009 |
| Business & Office Solutions & Services Ltd | Professional & scientific | 2015 |
| Business Divorce Limited | Information & communication | 2017 |
| Buy IT ANY Time Ltd | Other services | 2019 |
| BUZ SL Ltd | Construction | 2025 |
| BV European Business Management Limited | Professional & scientific | 2024 |
| BW Beauty & Aesthetics Academy Limited | Education | 2024 |
| BW Boutique Ltd | Wholesale & retail | 2023 |
| BY ALL Accounts Limited | Professional & scientific | 2009 |
| Bydecor Limited | Real estate | 1960 |
| Byford & Hammond Ltd | Construction | 2010 |
| Bytespec Limited | Information & communication | 2024 |
| C & D Cleaning Ltd | Administrative & support | 2020 |
| C & F Properties and Investments Limited | Real estate | 2007 |
| C & J Works Ltd | Construction | 2020 |
| C & L Estates Ltd | Real estate | 2019 |
| C Evans Scaffolding Limited | Construction | 2020 |
| C F Investments Essex Ltd | Construction | 2019 |
| C J N Projects Managements Limited | Construction | 2003 |
| C Mccaul Properties Ltd | Administrative & support | 2024 |
| C R Falk Plumbing and Heating Limited | Construction | 2011 |
| C T B Homes Limited | Real estate | 2021 |
| C&C Residential Limited | Real estate | 2023 |
| C&D Groundworks & Landscaping Ltd | Construction | 2022 |
| C&D Paving Limited | Construction | 2008 |
| C&D Resin and Landscapes Limited | Administrative & support | 2022 |
| C&H Properties Essex Ltd | Real estate | 2025 |
| C&S Aspen Ltd | Construction | 2017 |
| C&T Water Management Ltd | Water & waste | 2018 |
| C. Glasson Ltd | Real estate | 2023 |
| C. P. Cantwell & Co Limited | Construction | 2006 |
| C.C. Wood Ltd | Administrative & support | 2002 |
| C.I.E. Tours International (U.K.) Limited | Administrative & support | 1982 |
| C.I.P Decorators Limited | Construction | 2019 |
| Cacton Limited | Administrative & support | 2008 |
| CAD Printers Ltd | Manufacturing | 2025 |
| Caduceus Training and Operations Limited | Education | 2014 |
| Caffe Espresso Limited | Hospitality | 2015 |
| Cairns & Company (Developments) Limited | Construction | 2017 |
| Caledown Developments Ltd | Construction | 2026 |
| Callan Tuition Limited | Education | 2025 |
| Calleo Accountancy Limited | Professional & scientific | 2021 |
| Calm Seas Marketing Limited | Extraterritorial | 2015 |
| Calypso Trail Ltd | Administrative & support | 2015 |
| Cambridge R&D Academy Ltd. | Education | 2018 |
| Cammack Hiring Ltd | Financial services | 2023 |
| Camview Security Limited | Professional & scientific | 2002 |
| Canningdale Group Ltd | Financial services | 2024 |
| Canningdale Holdings Limited | Administrative & support | 2018 |
| Canningdale Mechanical Limited | Administrative & support | 2018 |
| Canningdale Services Limited | Professional & scientific | 1996 |
| Cantwell & Sons Ltd | Construction | 2011 |
| Capital Black Taxis Ltd | Transport & logistics | 2024 |
| Capital Car Company ( Essex) Ltd | Wholesale & retail | 2019 |
| Capital Fixing Limited | Construction | 2013 |
| Capital Projects (Infrastructure) Limited | Administrative & support | 2025 |
| Capitall Marquees Limited | Arts & recreation | 2004 |
| Capon Shipway & Co Limited | Professional & scientific | 2018 |
| Car OR Van Specialist Vehicle Hire Ltd | Administrative & support | 2011 |
| Carbon Delight Ltd | Extraterritorial | 2008 |
| Carfox Plant Hire Co.Limited | Real estate | 1955 |
| Carlton Road 1961 Limited | Extraterritorial | 2014 |
| Carpenters Arms Wickford Limited | Hospitality | 2022 |
| Carr Portable Buildings Limited | Manufacturing | 1971 |
| Carter and Ward of Wickford Limited | Construction | 1954 |
| Carter Sable Limited | Financial services | 2026 |
| Carters Consulting Limited | Information & communication | 2002 |
| Cassi's Braids Ltd | Other services | 2025 |
| Castle Cars (Essex) Ltd | Wholesale & retail | 2015 |
| Castle Point Maintenance Ltd | Construction | 2025 |
| Castledon Accounting Limited | Professional & scientific | 2015 |
| Castlefield Capital Partners Ltd | Financial services | 2021 |
| Catana Clothing Limited | Wholesale & retail | 2023 |