| Brand Clearance Limited | Other services | 2013 |
| Brandon Cooked Meats Limited | Wholesale & retail | 2008 |
| Brant Properties Limited | Real estate | 1986 |
| Brantwood Fast Fit Tyres Limited | Wholesale & retail | 2022 |
| Breakway Property Management Limited | Real estate | 2003 |
| Bree Management Limited | Households | 1989 |
| Breme Park Management Company Limited | Households | 2004 |
| Brent Symphony Orchestra Productions Limited | Arts & recreation | 2022 |
| Brewlabs Holdings Ltd | Financial services | 2017 |
| Brewlabs Solutions Limited | Professional & scientific | 2023 |
| BRI Logistic Ltd | Transport & logistics | 2026 |
| Briary Lodge (Beckenham) Management Company Limited | Households | 1989 |
| Brick House Port Loop Residents Management Company Limited | Households | 2019 |
| Brick Kiln Road (Stevenage) Management Company Limited | Households | 2007 |
| Bridge House Farm Management Company Limited | Households | 2003 |
| Bridgemead (Freemantle) Management Company Limited | Households | 1988 |
| Bridgemere (Burscough) Management Company Limited | Households | 2023 |
| Bridgewater Park Management Company Limited | Households | 1995 |
| Bridgitte Harley Hearing Care Limited | Health & social care | 2014 |
| Bright Future Electrics Limited | Construction | 2025 |
| Bright Start Nurseries Limited | Education | 2000 |
| Brighter Hearing Limited | Real estate | 2018 |
| Brighttemp Ltd | Administrative & support | 2020 |
| Brigid Fire Safety Ltd | Professional & scientific | 2025 |
| Briidge Solutions Ltd | Information & communication | 2025 |
| Brindle Park (Bamber Bridge) Management Company Limited | Households | 2022 |
| Brindley Edge (Hawkesbury) Management Company Limited | Households | 2021 |
| Brindley Park (Derby) Management Company Limited | Households | 2016 |
| Brindley Park (Phase 2) Management Company Limited | Households | 2017 |
| Brindley Village Management Company Limited | Households | 2009 |
| Brinkburn House (Dunston Riverside) Management NO 3 Limited | Households | 2002 |
| Brinkburn House (Dunston Riverside) Management NO. 8 Limited | Households | 2004 |
| Brinkburn House (Dunston Riverside) Management NO.4 Limited | Households | 2003 |
| Britannia Haulage Ltd | Construction | 2025 |
| Britannic Investments Limited | Real estate | 1997 |
| British & Overseas Meats Limited | Wholesale & retail | 1992 |
| Brix & Flix Ltd | Construction | 2025 |
| Broadsight Labs Ltd | Information & communication | 2026 |
| Broadstone Manor Diggle Apartments Management Company Limited | Households | 2024 |
| Broadstone Manor Diggle Management Company Limited | Households | 2024 |
| Broadwalk Holdings Limited | Extraterritorial | 2009 |
| Brook Meadow (Banbury) Management Company Limited | Households | 2005 |
| Brooke Bros (Smithfield) Ltd | Wholesale & retail | 1959 |
| Brookland (Hindley) Management Company Limited | Households | 2004 |
| Brookridge Court Management Company Limited | Real estate | 1999 |
| Brooks HGV Services Ltd | Transport & logistics | 2023 |
| Brookwood Residents Management Limited | Households | 1994 |
| Broship Limited | Wholesale & retail | 2017 |
| Brothership Commercial Limited | Wholesale & retail | 2026 |
| Brothership Social Limited | Wholesale & retail | 2026 |
| Brownacres Management Company Limited | Households | 2021 |
| Brownlow Farm Barns Limited | Households | 2004 |
| Broxbourne Selfstore Limited | Other services | 2022 |
| Brso Construction Ltd | Construction | 2021 |
| Bruna Property Ltd | Real estate | 2025 |
| Brunilda Ltd | Wholesale & retail | 2021 |
| Brunswick Heights (Wednesbury) Management Company Limited | Households | 2004 |
| Bsit Ltd | Real estate | 2025 |
| Buchanan Gardens Management Company Limited | Households | 2006 |
| Buckingham Court Management (Plots 1-28) Limited | Households | 1994 |
| Buckley House (Freehold) Limited | Households | 2001 |
| Buckshaw Village Management Company Limited | Households | 2003 |
| Building Relations Ltd | Professional & scientific | 2014 |
| Buildingworks & Maintenance Limited | Construction | 2011 |
| Buildpro Limited | Construction | 2011 |
| Buildrow Property Services Ltd | Other services | 2018 |
| Buntingford Dairies Ltd | Wholesale & retail | 2026 |
| Burbidge Maintenance Services Limited | Construction | 2001 |
| Burcuaras Ltd | Hospitality | 2022 |
| Burford House (Freehold) Limited | Households | 2018 |
| Burford House Management Company Limited | Households | 2002 |
| Burges Road Management Company Limited | Households | 1991 |
| Burghley Court (Doncaster) Management Company Limited | Administrative & support | 2015 |
| Burke Associates Ltd | Professional & scientific | 2011 |
| Burlington Apartments Management Company Limited | Households | 2011 |
| Burtonlaine Limited | Manufacturing | 2022 |
| Buryfields Maltings (Ware) Management Company Limited | Households | 2003 |
| Business Impact Consulting Ltd | Professional & scientific | 2024 |
| Busy Bees 4 Life Ltd | Professional & scientific | 2020 |
| Busy Lizzies Kids Club Limited | Education | 2014 |
| Butcher Property Rentals Limited | Real estate | 2026 |
| Butler Haydon Associates Limited | Professional & scientific | 2010 |
| Butler Physiotherapy Ltd | Health & social care | 2019 |
| Buy & Sale EE Ltd | Transport & logistics | 2024 |
| Buzz Racing Ltd | Wholesale & retail | 2015 |
| Buzz SV Group Limited | Wholesale & retail | 2025 |
| BW Herts Limited | Real estate | 2016 |
| Bydand Lane Management Company Limited | Households | 2012 |
| Byron House (Residents) Limited | Households | 1986 |
| Bytech Dental LAB Limited | Health & social care | 2013 |
| C & C Kitchens Ltd. | Wholesale & retail | 2007 |
| C & J Vehicle Sales Ltd | Wholesale & retail | 2018 |
| C & L Carpentry Ltd | Construction | 2013 |
| C a Condon Limited | Construction | 2023 |
| C. G. a. Investments Ltd. | Real estate | 2017 |
| C. Newman Electrical Limited | Construction | 2002 |
| C. R. Barron (Markets) Limited | Wholesale & retail | 1961 |
| C. R. Barron (Southern) Limited | Wholesale & retail | 1951 |
| C.A.J. Management Ltd | Financial services | 2022 |
| C.Amorosi Limited | Construction | 2017 |