| Bradwell Assets Limited | Hospitality | 2016 |
| Bradwell Trading Ltd | Real estate | 2016 |
| Brady Ives Limited | Construction | 2013 |
| Braeburn Gardens (Bures) Management Company Limited | Households | 2013 |
| Braemar Globe Limited | Wholesale & retail | 2017 |
| Brag Communications Limited | Professional & scientific | 2015 |
| Braidwood (One) Management Company Limited | Households | 2002 |
| Brains Analytica Ltd | Information & communication | 2019 |
| Braintree Cricket Club Limited | Real estate | 1996 |
| Braintree Motor Works Ltd | Wholesale & retail | 2012 |
| Brainwaves Education Limited | Education | 2003 |
| Braiseworth Orchards Limited | Agriculture & fishing | 2001 |
| Braiswick Chase Management Company Limited | Households | 2024 |
| Braiswick Consulting Ltd | Professional & scientific | 2022 |
| Braiswick Management Company Limited | Households | 2024 |
| Braiswick Tyres Limited | Wholesale & retail | 2001 |
| Braiswick View Management Company Limited | Households | 2003 |
| Braiswick Wealth Management Limited | Professional & scientific | 2020 |
| Brajeff Properties Limited | Real estate | 2024 |
| Brakeaway Bike Tours Ltd | Arts & recreation | 2013 |
| Bramen Limited | Professional & scientific | 2012 |
| Bramley & Co Ltd | Hospitality | 2014 |
| Brampton Commercial Management Limited | Professional & scientific | 2024 |
| Bramwood Management Company Limited | Real estate | 2019 |
| Bramwood Property Development Limited | Construction | 2015 |
| Branch Designs Ltd | Manufacturing | 2026 |
| Brand Life Consultancy Ltd | Administrative & support | 2009 |
| Brandart Limited | Administrative & support | 2011 |
| Brandboost Limited | Extraterritorial | 2001 |
| Brandh Corp Ltd | Wholesale & retail | 2025 |
| Brandon Trading Limited | Wholesale & retail | 2013 |
| Brands Direct Limited | Professional & scientific | 1995 |
| Brandworks Health & Fitness Ltd | Health & social care | 2022 |
| Brandywine Communications UK Ltd | Manufacturing | 1991 |
| Braneth Limited | Construction | 2018 |
| Branshan Healthcare Group Ltd | Health & social care | 2023 |
| Brasa Street Ltd | Hospitality | 2025 |
| Bratt Media Ltd | Wholesale & retail | 2023 |
| Braunco Ltd | Construction | 2011 |
| Bravace Properties Ltd | Real estate | 2023 |
| Bravo Traders Ltd | Wholesale & retail | 2026 |
| BRC Construction 2025 Ltd | Construction | 2025 |
| BRC Projects Limited | Construction | 2016 |
| Brdcouriers Ltd | Transport & logistics | 2018 |
| Bread and Circuses Limited | Information & communication | 2002 |
| Breadmore Webb Estate Agents Limited | Real estate | 2011 |
| Breakdown Consultancy Ltd | Professional & scientific | 2024 |
| Breakdown Research Ltd | Professional & scientific | 2023 |
| Breakfree Holidays Limited | Administrative & support | 2006 |
| Breakthru Investments Limited | Administrative & support | 2016 |
| Breckland Travel Limited | Administrative & support | 2007 |
| Breede River Investments | Financial services | 2025 |
| Breese (Fitness 2020) Limited | Wholesale & retail | 2020 |
| Breewood Consulting Limited | Information & communication | 2023 |
| Breeze Underwriting Limited | Financial services | 2013 |
| Brendan Boyle Bloodstock Ltd | Agriculture & fishing | 2014 |
| Brennan Competency Assessment Ltd | Other services | 2014 |
| Brennan Construction & Developments Ltd | Construction | 2026 |
| Brennan Holdings Limited | Financial services | 2019 |
| Brennan Limited | Construction | 1993 |
| Brent Hall Road Management Company Limited | Real estate | 2022 |
| Brentwood CAP Limited | Hospitality | 2019 |
| Brettfield Developments Limited | Administrative & support | 2000 |
| Brettfield Investments Limited | Real estate | 2024 |
| Brewery Tower Management Limited | Real estate | 1991 |
| Brews & Whiskers Ltd | Hospitality | 2024 |
| Briam Electrical Contractors Limited | Construction | 2007 |
| Brian Reves Ltd | Wholesale & retail | 2025 |
| Briar House Partners Limited | Professional & scientific | 2018 |
| Briargate Properties Limited | Hospitality | 2021 |
| Briarsford MOT, Service & Repair Centre Ltd. | Wholesale & retail | 2007 |
| Brick and Field Ltd | Financial services | 2024 |
| Brick Kiln (Beccles) Management Company Limited | Households | 2016 |
| Bricket Wood Care Limited | Health & social care | 2015 |
| Bricklawn Limited | Construction | 2004 |
| Bricklayers Social Club Ltd | Other services | 2022 |
| Bricknel Close (Castle Acre) Management Company Limited | Households | 2022 |
| Brickwell Court ( Earls Colne ) Maintenance Limited | Households | 2014 |
| Brictemple Care Limited | Health & social care | 2025 |
| Bridge House (Upminster) Limited | Health & social care | 2002 |
| Bridge the GAP (BTG) Limited | Professional & scientific | 2025 |
| Bridged Hearts Ltd | Health & social care | 2024 |
| Bridgeman Bookkeeping Ltd | Professional & scientific | 2013 |
| Bridgetrack Ltd | Education | 2003 |
| Bridging VAT Limited | Financial services | 2018 |
| Brierley Paddocks Management Limited | Households | 2002 |
| Briflyte Limited | Real estate | 2019 |
| Bright Contractors Ltd | Construction | 2016 |
| Bright Field Consulting Ltd | Professional & scientific | 2013 |
| Bright Field Education Ltd | Professional & scientific | 2026 |
| Bright Hire Solutions Limited | Administrative & support | 2024 |
| Bright Home Living Ltd | Administrative & support | 2025 |
| Bright Idea Staffing Limited | Administrative & support | 2022 |
| Bright Independent Consulting Ltd | Professional & scientific | 2021 |
| Bright Lives Group Limited | Health & social care | 2020 |
| Bright Lives Ltd | Health & social care | 2020 |
| Bright Lives Social Enterprise C.I.C. | Education | 2012 |
| Bright Minds Centre Limited | Health & social care | 2026 |
| Bright Minds Group Limited | Real estate | 2018 |
| Bright Sea Homes Limited | Real estate | 2020 |