| Brooke Tatchell Ltd | Professional & scientific | 2022 |
| Brooke Tatchell Properties Ltd | Real estate | 2025 |
| Brookfield M&E Ltd | Administrative & support | 2019 |
| Brooks Fishmongers Limited | Wholesale & retail | 2007 |
| Broomfield Cambridge Limited | Real estate | 2024 |
| Broomfield Opticians Limited | Professional & scientific | 2005 |
| Broomfield UK Holdings Ltd | Other services | 2024 |
| Browns Heating Services Ltd | Construction | 2015 |
| Bryan Joseph & Co Limited | Construction | 2003 |
| BSA Homes Ltd | Real estate | 2018 |
| Bsdt Films Ltd | Information & communication | 2014 |
| BSH Upminster Ltd | Health & social care | 2022 |
| Bspoqe Limited | Information & communication | 2019 |
| BSR Haulage Logistics Limited | Transport & logistics | 2019 |
| Bsskandia Ltd | Wholesale & retail | 2016 |
| Btpt Ltd | Professional & scientific | 2013 |
| BTX Godske Group UK Ltd | Manufacturing | 1999 |
| Buckhurst Hill FC Foundation | Arts & recreation | 1998 |
| Buckhurst Hill Football Club Limited | Arts & recreation | 2021 |
| Bucksbridge Flat Management Limited | Real estate | 2001 |
| Build 46 Limited | Construction | 2018 |
| Build Brighton and Hove Limited | Construction | 2017 |
| Build OK Ltd | Construction | 2022 |
| Buildari Limited | Construction | 2026 |
| Buildbits Limited | Professional & scientific | 2023 |
| BUILDING17 Ltd | Professional & scientific | 2021 |
| Buildings & Homes Contractors Limited | Construction | 2022 |
| Buildsmith Brighton Limited | Construction | 2014 |
| Buildtech Consult Ltd | Professional & scientific | 2007 |
| Bullman Holdings Limited | Extraterritorial | 1994 |
| Bunnyway Nominee Limited | Information & communication | 2024 |
| Bunnyway UK Ltd | Information & communication | 2024 |
| Burcunova Limited | Hospitality | 2025 |
| Burden Contractors Limited | Construction | 2010 |
| Burlacu Glazing Ltd | Construction | 2020 |
| Burndata Limited | Real estate | 1997 |
| Burstead Bears Day Nursery Limited | Other services | 2005 |
| Bushey Point Limited | Real estate | 2023 |
| Bushi Plumbing & GAS Ltd | Construction | 2024 |
| Business and Marriage Consulting Limited | Professional & scientific | 2020 |
| Business Psychology Solutions Limited | Administrative & support | 2014 |
| Buster Property Company Ltd | Real estate | 2021 |
| Butterfields Gems Limited | Administrative & support | 1999 |
| Buzz Bricks Limited | Real estate | 2025 |
| Buzz Talent Social Media Limited | Professional & scientific | 2019 |
| Bxmedia Limited | Administrative & support | 2024 |
| BY F Socials Limited | Professional & scientific | 2025 |
| BY Kizzie Ltd | Wholesale & retail | 2025 |
| Byaces Ltd | Wholesale & retail | 2024 |
| Byblos Harbour Express Ltd | Real estate | 2009 |
| Byrne’S Plumbing and Heating Services Ltd | Construction | 2025 |
| Byron Court Apartments Limited | Households | 1965 |
| Byron-Butler Corporation Ltd | Information & communication | 2014 |
| Byte Buzz IT Solutions Ltd | Information & communication | 2025 |
| Bytegeist Limited | Information & communication | 2014 |
| BZ Ventures Ltd | Wholesale & retail | 2026 |
| C & a Seafoods (Billingsgate) Limited | Wholesale & retail | 1983 |
| C & M Real Estate Ltd | Real estate | 2007 |
| C D Fine Edge Limited | Wholesale & retail | 2026 |
| C G N Haulage Ltd | Transport & logistics | 2022 |
| C M Engineering Personnel Limited | Construction | 1998 |
| C O'Mahony Limited | Hospitality | 2014 |
| C Ottley Ltd | Manufacturing | 2026 |
| C P Bakery Innovations LLP | | 2024 |
| C Stefanescu Electrical Services Limited | Energy | 2014 |
| C W Decorating Services Limited | Construction | 2004 |
| C&Dm Estates Limited | Real estate | 2022 |
| C.Cdg. Ltd | Construction | 2017 |
| C.F Bevis Limited | Professional & scientific | 1998 |
| C.S.R. Europe Limited | Administrative & support | 2008 |
| C3 City Construction Company Ltd | Construction | 2015 |
| CAB Media Ltd | Administrative & support | 2012 |
| CAC78 Ltd | Construction | 2018 |
| Cafe Boba Ltd | Wholesale & retail | 2025 |
| Cafe Salford Ltd | Hospitality | 2017 |
| Cahani Drylining & Finishing Ltd | Construction | 2010 |
| Caitarvi Limited | Real estate | 2022 |
| Californian Limited | Manufacturing | 2021 |
| Call Nico Ltd | Construction | 2006 |
| Callisto Consultancy Limited | Professional & scientific | 2017 |
| Calum Finlay Limited | Other services | 2015 |
| Calvert Investment Group Limited | Administrative & support | 2024 |
| Calvin June Property Limited | Real estate | 2025 |
| Calyro Limited | Professional & scientific | 2025 |
| CAM Install Services Limited | Construction | 2026 |
| Camberwell Dwellings Ltd | Real estate | 2022 |
| Camberwell House Limited | Real estate | 2020 |
| Cambridge Serviced Apartments Ltd | Hospitality | 2019 |
| Campany Ltd | Construction | 2011 |
| Campbell Residential Ltd | Real estate | 2011 |
| Camy Developments Limited | Real estate | 2025 |
| CAN Kardes UK Ltd | Hospitality | 2017 |
| CAN Private Ltd | Other services | 2022 |
| Cancut Edit Limited | Information & communication | 2016 |
| Candler Consultants Ltd | Professional & scientific | 2012 |
| Candles by Sarah Limited | Administrative & support | 2021 |
| Canjay Investments Limited | Real estate | 2018 |
| Cann Invest 1 Ltd | Administrative & support | 2025 |
| Canning Property Holdings Ltd | Real estate | 2026 |
| Canty Consultants Ltd | Professional & scientific | 2021 |