| Bunny & Bear Limited | Hospitality | 2024 |
| Burgerz & Bitez LOS Ltd | Hospitality | 2025 |
| Burnett's of Essex Limited | Transport & logistics | 2016 |
| Burrett Hospitality Ltd | Hospitality | 2025 |
| Burt Group Limited | Administrative & support | 2012 |
| Burty Ltd | Administrative & support | 2012 |
| BUS 62 Ltd | Transport & logistics | 2018 |
| Bush Building Maintenance Limited | Administrative & support | 2013 |
| Business Skills Network Limited | Professional & scientific | 2023 |
| Business Tuning Limited | Other services | 2010 |
| Businesswow Ltd | Information & communication | 2019 |
| Busy Flippers Limited | Real estate | 2019 |
| Butler Engineering International Ltd | Professional & scientific | 2022 |
| Butlers Financial Limited | Professional & scientific | 2009 |
| Butterfly Barn Consulting Limited | Professional & scientific | 2025 |
| Buzz People Recruitment Ltd | Administrative & support | 2012 |
| Bwjm Consulting Limited | Information & communication | 2026 |
| BY Georgina Limited | Other services | 2016 |
| BY John Lawson Limited | Hospitality | 2016 |
| BYE Cat Fish Ltd | Other services | 2023 |
| Byfield Engineering Limited | Construction | 1989 |
| Byron Investments Essex Limited | Households | 2022 |
| C & B Services Limited | Real estate | 1994 |
| C & C Infrastructure Ltd | Administrative & support | 2021 |
| C & N Fencing Ltd | Administrative & support | 2025 |
| C & N Solutions Ltd | Construction | 2021 |
| C Budd Management Limited | Professional & scientific | 2019 |
| C D Johnston Limited | Construction | 2017 |
| C J Doors Limited | Construction | 2006 |
| C M W Equipment Holdings Limited | Wholesale & retail | 2010 |
| C P S Upholstery Ltd | Manufacturing | 2021 |
| C Print Media Limited | Manufacturing | 2011 |
| C View Security Southend Ltd | Administrative & support | 2026 |
| C&G Prestige Bathrooms Ltd | Construction | 2022 |
| C&H Fire Protection Ltd | Public administration | 2020 |
| C&H Traffic Solutions Ltd | Construction | 2025 |
| C&H UK Holdings Limited | Financial services | 2024 |
| C&P Investment Holdings Ltd | Extraterritorial | 2012 |
| C&R Crystal Clear Cleaning Ltd | Administrative & support | 2024 |
| C&T Business Sales Limited | Real estate | 2014 |
| C. Higgins Engineering Limited | Professional & scientific | 2015 |
| C.B.S. Maintenance Services Limited | Construction | 1986 |
| C.F. Roofing (Essex) Limited | Construction | 2012 |
| C.L.S Diagnostics Ltd | Health & social care | 2022 |
| C.S.S. Construction Limited | Construction | 2019 |
| C.S.W Interiors Limited | Professional & scientific | 2016 |
| C.W.T. Advertising Ltd | Professional & scientific | 2003 |
| Cableandsocket.Co.Uk Limited | Extraterritorial | 2018 |
| CAD Transport Ltd | Transport & logistics | 2012 |
| Caedis Consulting Ltd | Professional & scientific | 2026 |
| Caesium Limited | Health & social care | 2013 |
| Cafe Fish Limited | Hospitality | 2018 |
| Cake Craft by Charlotte and MAY Ltd | Wholesale & retail | 2020 |
| Calahans Fleet Services Ltd | Wholesale & retail | 2025 |
| Calahans Services UK Limited | Administrative & support | 2022 |
| Calahans Transport Services Ltd | Transport & logistics | 2019 |
| Calibre Creative Limited | Professional & scientific | 2024 |
| Calibre Print & Display Ltd | Wholesale & retail | 2017 |
| Call Print Express Limited | Manufacturing | 2005 |
| Callahans Cleaning Services UK Ltd | Administrative & support | 2022 |
| Callas Consultants Limited | Professional & scientific | 2025 |
| Callswift Limited | Other services | 1993 |
| Calooper Ltd | Administrative & support | 2023 |
| Calypto Content Ltd | Professional & scientific | 2025 |
| Cameron Analytics Limited | Professional & scientific | 2015 |
| Cameron Management Limited | Administrative & support | 1981 |
| Cameron Miller Property Management Limited | Extraterritorial | 2018 |
| Campus Coaching Services GB Limited Limited | Education | 1976 |
| Candied Gentry Limited | Hospitality | 2025 |
| Candu Self Drive Hire Ltd | Administrative & support | 2011 |
| Cane & Davis Limited | Other services | 2025 |
| Cannell Consulting Limited | Education | 2003 |
| Cannell Development Limited | Real estate | 2019 |
| Cansure Limited | Professional & scientific | 2019 |
| Canuck Limited | Professional & scientific | 2022 |
| CAO Bros Ltd. | Hospitality | 2015 |
| Capella Produce Ltd | Wholesale & retail | 2015 |
| Capex Currency Ltd | Administrative & support | 2017 |
| Capital Clearance Holdings Ltd | Administrative & support | 2024 |
| Capital Engineering Personnel Limited | Administrative & support | 1971 |
| Capricorn Financial Mortgages Limited | Financial services | 2006 |
| Capstone Real Estate London Ltd | Real estate | 2024 |
| Car Kingdom Ltd | Wholesale & retail | 2024 |
| Cara DE LA Hoyde Limited | Other services | 2014 |
| Cardiac Care Services Ltd | Health & social care | 2003 |
| Care Advisory Limited | Professional & scientific | 2025 |
| Care Connected Ltd | Other services | 2012 |
| Care Express Ltd | Real estate | 2015 |
| Care Jobs Essex Castle Point Limited | Health & social care | 2020 |
| Care Syndicate AI Ltd | Administrative & support | 2026 |
| Careessence Limited | Administrative & support | 2005 |
| Cariad Wellness Group Limited | Health & social care | 2023 |
| Caribbean Foods Ltd | Manufacturing | 2023 |
| Carlton Avenue Investments Limited | Real estate | 2020 |
| Carly Harrison Ltd | Information & communication | 2017 |
| Carnaby Engineering Limited | Professional & scientific | 2025 |
| Carnaby Motor Services Ltd | Wholesale & retail | 2022 |
| Carneco Foods Limited | Extraterritorial | 2013 |
| Carneco Investments Limited | Wholesale & retail | 1987 |
| Caron Property Investments Limited | Real estate | 2025 |