| Betterway Building Ltd. | Manufacturing | 2019 |
| Beyond Trading Group LLP | | 2019 |
| BID4SPORT Limited | Wholesale & retail | 2010 |
| BID4SPORT.COM Limited | Wholesale & retail | 2008 |
| Bill Tech Limited | Professional & scientific | 2023 |
| Birds Green Services Limited | Professional & scientific | 2015 |
| BIZ Image Group Ltd | Wholesale & retail | 2018 |
| BJ One Contracts Ltd | Real estate | 2013 |
| Blackbirds Recruitment & Consultancy Ltd | Administrative & support | 2023 |
| Blackraven Developments Limited | Real estate | 2004 |
| Blake Hall Weddings and Events Limited | Real estate | 2016 |
| Blend EXT Co Limited | Other services | 2026 |
| Bloomin Jacks Kitchen Ltd | Hospitality | 2019 |
| Bloomin Jacks Ltd | Wholesale & retail | 2016 |
| BLU Properties & Investment Limited | Real estate | 2021 |
| Bluebell Home Improvements Limited | Wholesale & retail | 2022 |
| Bluestocking Health Limited | Professional & scientific | 2026 |
| Blush & Blow Ongar Limited | Other services | 2025 |
| Boatmans Limited | Wholesale & retail | 2012 |
| Body Camp App Ltd | Arts & recreation | 2023 |
| Bower Group Holdings Limited | Financial services | 2023 |
| Bower Group Limited | Financial services | 2021 |
| Bower Home Finance Limited | Financial services | 2019 |
| Bower Retirement Limited | Financial services | 2006 |
| Bower Wealth Limited | Financial services | 2020 |
| Bows of Blue (London) Limited | Wholesale & retail | 2025 |
| Box Electrical Ltd | Construction | 2023 |
| BOX2BOX Football Limited | Arts & recreation | 2022 |
| Breakout-Interiors Ltd | Manufacturing | 2019 |
| Brentwood Electrical Ltd | Energy | 2018 |
| Brewery Yard Management Ltd | Households | 2018 |
| Bricklayers Arms (Brentwood) Ltd | Hospitality | 2022 |
| Brigden Properties Limited | Real estate | 2018 |
| Bright Ideas (GB) Ltd | Manufacturing | 1988 |
| Bright Stars Pre-School Community Interest Company | Education | 2009 |
| Brinka Boutique UK Ltd | Wholesale & retail | 2025 |
| Britton Construction Group Ltd | Construction | 2026 |
| Brook Lodge Ongar RTM Company Limited | Administrative & support | 2014 |
| Brummell Place Old Harlow Management Limited | Real estate | 2005 |
| BSU Broking Ltd | Financial services | 2023 |
| Buddy Bottle Ltd | Wholesale & retail | 2023 |
| Building Design Services (Bromley) Limited | | 1987 |
| Burnsbuild Essex Limited | Construction | 2022 |
| Burnsbuild Ltd | Construction | 2015 |
| Burrill Consultants Limited | Information & communication | 2020 |
| Burrill Young Limited | Other services | 2020 |
| BY SME Ltd | Professional & scientific | 2018 |
| C S Watson & Co Limited | Professional & scientific | 2003 |
| Cairns Topco Limited | Arts & recreation | 2026 |
| Cakeybakeydoodaa Ltd | Manufacturing | 2020 |
| Calidad Facades Limited | Construction | 2017 |
| Calisota Accounting Ltd | Professional & scientific | 2024 |
| Calisota Global Ltd | Professional & scientific | 2025 |
| Callaghan Property and Lets Ltd | Real estate | 2020 |
| Calsmar Ltd | Health & social care | 2026 |
| Capital Ace Holdings Ltd | Financial services | 2024 |
| Capital Ace Limited | Information & communication | 1999 |
| Capmarv Associates Limited | Financial services | 2016 |
| Carbon KMK Limited | Wholesale & retail | 2026 |
| Carerose Cares Services Ltd | Other services | 2021 |
| Carlton Developments (Clacton) Ltd. | Construction | 2017 |
| Carton Packaging 2020 Ltd | Manufacturing | 2017 |
| Casa Monte Cristo Limited | Administrative & support | 2006 |
| Catering by A&S Ltd | Hospitality | 2023 |
| Catherine Lurie Associates Limited | Wholesale & retail | 2021 |
| Cavendish Wealth Ltd | Real estate | 2023 |
| CBC Maintenance Services Ltd | Water & waste | 2011 |
| CBW Clearances Ltd | Water & waste | 2020 |
| Ccressey Ltd | Administrative & support | 2022 |
| Central Beauty Ltd | Other services | 2013 |
| Cerox Coating Ltd | Wholesale & retail | 2026 |
| CG Financial LLP | | 2009 |
| CGS Alpha Limited | Financial services | 2024 |
| CGS Construction London Ltd | Construction | 2013 |
| Chamberlayne Limited | Financial services | 2013 |
| Chandler Cabling Services Ltd | Construction | 2012 |
| Chariot Storage and Logistics Ltd | Transport & logistics | 2022 |
| Charles Rookwood Holdings Limited | Agriculture & fishing | 2017 |
| Charles Rowe(Rookwood)Limited | Agriculture & fishing | 1959 |
| Chase Thermal Ltd | Professional & scientific | 2025 |
| Cheema Electrical Contractors Ltd | Extraterritorial | 2023 |
| Chelmz Solutions Ltd | Health & social care | 2021 |
| CHEMA62 Ltd | Hospitality | 2025 |
| Chester Electrics Limited | Construction | 2014 |
| Chevers Hall Barns Management Limited | Households | 2002 |
| Chris K Consulting Limited | Information & communication | 2025 |
| Chris Mitchell Ltd | Other services | 2013 |
| Chris.Haines-Education Ltd | Education | 2015 |
| Christopher William Building Solutions Ltd | Construction | 2010 |
| Churchfields (South Woodford) Management Limited | Households | 1978 |
| Cirrus Court (Upminster) Ltd | Households | 2007 |
| CJ Surveying Consultants Limited | Professional & scientific | 2011 |
| Claus Outsourcing Advisors and Management Ltd | Construction | 2021 |
| Cleartec IT Group Limited | Information & communication | 2005 |
| Clerkenwell RUG Studio Limited | Wholesale & retail | 2014 |
| Cloverleaf Associates (Clacton) Limited | Extraterritorial | 2017 |
| Cloverleaf Associates (Harold Park) Limited | Hospitality | 2016 |
| Cloverleaf Associates (Lakeside) Limited | Hospitality | 2016 |
| Cloverleaf Associates (Ockendon) Limited | Hospitality | 2016 |
| Cloverleaf Industries Limited | Hospitality | 2014 |