| Brain Quest Consultants Limited | Information & communication | 2015 |
| Brainfinder Ltd | Professional & scientific | 2012 |
| Brainy Maths LAB Limited | Education | 2025 |
| Brambledown Properties Limited | Real estate | 2015 |
| Bramdean Court Management Company Limited | Households | 1990 |
| Bramdean Village (One) Management Company Limited | Households | 2012 |
| Bramdean Village (Three) Management Company Limited | Households | 1988 |
| Bramdean Village (Two) Management Company Limited | Households | 1988 |
| Bramford Court (High Street Southgate) Limited | Households | 1976 |
| Bramley Health Holding Company Limited | Health & social care | 2010 |
| Bramley Health Limited | Health & social care | 1996 |
| Bramley Health Property Holdings Limited | Households | 2023 |
| Bramley Health Support Services Ltd | Health & social care | 2015 |
| Brancek Medical Limited | Health & social care | 2015 |
| Brand Sourcing Ltd | Wholesale & retail | 2016 |
| Branded by X Limited | Wholesale & retail | 2011 |
| Brandevity Ltd | Information & communication | 2025 |
| Brandez Limited | Real estate | 2023 |
| Brandiann Ltd | Hospitality | 2022 |
| Branding Apparel Ltd | Wholesale & retail | 2018 |
| Brandly Ventures Ltd | Manufacturing | 2022 |
| Brando AC Ltd | Professional & scientific | 2023 |
| Brandon’S Building and Maintenance Ltd | Construction | 2025 |
| Brandram RD Community Centre Limited | Other services | 2016 |
| Brands by Barry Ltd | Professional & scientific | 2019 |
| Brands LAB Limited | Professional & scientific | 2016 |
| Brandt ABC Ltd. | Real estate | 1981 |
| Brandt Computer Systems Limited | Information & communication | 1977 |
| Brandt Holdings Limited | Information & communication | 1985 |
| Brandum Limited | Manufacturing | 2023 |
| Brangabo Build Limited | Extraterritorial | 2021 |
| Brantwood Residents Association Limited | Households | 1983 |
| Brasa E MAR Ltd | Hospitality | 2026 |
| Brasswell Properties Limited | Real estate | 1998 |
| Brathway Management Company (Buchanan House) Limited | Households | 1988 |
| Brave Flowers Ltd | Other services | 2017 |
| Brave Frozen Tree Ltd | Manufacturing | 2025 |
| Bravest Developments Ltd | Construction | 2025 |
| Bravo Builders Ltd | Construction | 2026 |
| Bravura Architects Limited | Construction | 2003 |
| Braymarsh Cash Ltd | Wholesale & retail | 2011 |
| Brazuk Decorating Ltd | Construction | 2024 |
| BRB Enterprises Ltd | Wholesale & retail | 2018 |
| Bread & Beyond Limited | Wholesale & retail | 2018 |
| Bread Consulting Limited | Administrative & support | 2009 |
| Bread Tree Ltd | Hospitality | 2014 |
| Breadthwork Ltd | Health & social care | 2021 |
| Breakdown Medic Ltd | Wholesale & retail | 2023 |
| Breaking Free Ltd | Professional & scientific | 2025 |
| Breakthrough Medical Services Ltd | Health & social care | 2023 |
| Breamore Ancient Buildings Conservation Trust | Arts & recreation | 1990 |
| Breamore Estate Company (Management) Limited | Construction | 2024 |
| Breamore Estate Company Limited | Agriculture & fishing | 1959 |
| Breast Clinic Kent Limited | Health & social care | 2023 |
| Breath Moments Ltd | Wholesale & retail | 2025 |
| Breathless Beauty Ltd | Other services | 2026 |
| Breckenbrough Flats Management Company Limited | Households | 1995 |
| Brello Limited | Real estate | 2021 |
| Brenda Scanlan Consulting Limited | Professional & scientific | 2016 |
| Brendex Services Limited | Health & social care | 2014 |
| Brennan Safety Solutions Limited | Professional & scientific | 2016 |
| Brent Property Developments Limited | Construction | 2016 |
| Brentford Developments Limited | Real estate | 1986 |
| Brentford Lock (Herons View Phase) Management Company Limited | Households | 2004 |
| Brentford Lock High Street Phase Management Company Limited | Households | 2003 |
| Brentford Lock Management Company Limited | Households | 2003 |
| Brentside Management Co. Limited | Construction | 1989 |
| Bressenden Sushi Ltd | Hospitality | 2016 |
| Bretforton Village (Bretforton) Management Company Limited | Households | 2014 |
| Brettic Limited | | 1984 |
| Brew & Cake Ltd | Hospitality | 2024 |
| Brewery Wharf Residents Management Company Limited | Professional & scientific | 2014 |
| BRG Vans Limited | Transport & logistics | 2015 |
| Briar Patch Management Company Limited | Households | 2007 |
| Briar Rose Management Company Limited | Households | 2006 |
| Briarleas (Cranham) Residents Association Limited | Households | 1970 |
| Briarwood (Bolton) Management Company Limited | Households | 2010 |
| Bricfab Limited | Construction | 2017 |
| Brick and Barrel Ltd | Hospitality | 2025 |
| Brick Tastic Limited | Real estate | 2024 |
| Brickayla Property Limited | Real estate | 2026 |
| Bricksblocks Childminding Ltd | Health & social care | 2021 |
| Bridge Building Supplies Limited | Wholesale & retail | 2008 |
| Bridge Community | Education | 2019 |
| Bridge House Management (South Croydon) Limited | Households | 1989 |
| Bridge House Residents Association Limited | Households | 2003 |
| Bridge House Supported Living Ltd | Health & social care | 2021 |
| Bridge Mangal Ltd | Hospitality | 2024 |
| Bridge News and Stores Limited | Wholesale & retail | 2025 |
| Bridge Training (UK) Ltd | Education | 2010 |
| Bridgestock 333 Limited | Real estate | 2025 |
| Bridgewalk Limited | Households | 2007 |
| Bridgewater Computer Services Limited | | 1986 |
| Bridging Boundaries Ltd | Education | 2026 |
| Bridgwater House Management Company Limited | Households | 2003 |
| Bright Beginners Daycare Ltd | Health & social care | 2021 |
| Bright Blue Cleaning Services Ltd | Administrative & support | 2025 |
| Bright Buds Ltd | Education | 2024 |
| Bright Decor London Ltd | Construction | 2023 |
| Bright Imaging Limited | Health & social care | 2025 |