| Breaking the Silence Limited | Administrative & support | 2016 |
| BREAKTHROUGH2PERFORMANCE Limited | Professional & scientific | 2012 |
| Breathwithzey Ltd | Health & social care | 2021 |
| Breconcherry Limited | Manufacturing | 1971 |
| Breeze Ride Limited | Administrative & support | 2025 |
| Breezing Properties Ltd | Real estate | 2020 |
| Brego Ltd | Information & communication | 2021 |
| Breman Ltd | Manufacturing | 2025 |
| Bremps Foods Limited | Manufacturing | 2023 |
| Bremps Logistics Ltd | Wholesale & retail | 2025 |
| Brenda Edwards Global Ltd | Information & communication | 2019 |
| Brent Creative Ltd | Wholesale & retail | 2008 |
| Brent Europe Limited | Extraterritorial | 1975 |
| Brentcast Limited | Financial services | 1987 |
| Brenton Ltd | Wholesale & retail | 2012 |
| Brett Concept Limited | Professional & scientific | 2021 |
| Brettish Property & Services Ltd | Real estate | 2021 |
| Brevis Ltd | Information & communication | 2023 |
| Brew & Spice Co Ltd | Wholesale & retail | 2024 |
| Brew Brokers Ltd. | Information & communication | 2017 |
| Brew Day Limited | Wholesale & retail | 2021 |
| Brewery TAP House Limited | Hospitality | 1998 |
| Brewstar Capital Ltd | Professional & scientific | 2021 |
| Brian Clifford Limited | Professional & scientific | 2008 |
| Brian COX Sales Limited | Real estate | 2025 |
| Brian Currie (Milton Keynes) Limited | Wholesale & retail | 1982 |
| Brian Mays F.L.T. Training Ltd | Education | 2018 |
| Brian Productions Limited | Information & communication | 2003 |
| Brian Robson Coachworks Limited | Wholesale & retail | 1988 |
| Briar Properties Limited | Real estate | 2007 |
| Brice Automotive Limited | Wholesale & retail | 2022 |
| Brick by Brick Investments Ltd | Real estate | 2017 |
| Brick Festival Limited | Arts & recreation | 2023 |
| Brickhill Construction Ltd | Construction | 2019 |
| Brickhill Fabrications Limited | Manufacturing | 2023 |
| Brickhill Forge Ltd | Agriculture & fishing | 2002 |
| Brickhill Holdings Ltd | Real estate | 2018 |
| Brickhill Homes (Brackley) Ltd | Real estate | 2021 |
| Brickhill Homes (Linmere 2) Ltd | Construction | 2022 |
| Brickhill Homes (Luton) Ltd | Construction | 2022 |
| Brickhill Homes Developments Ltd | Construction | 2021 |
| Brickhill Homes Ltd | Real estate | 2015 |
| Brickhill Limited | Professional & scientific | 2013 |
| Brickhill Properties (MK) Limited | Real estate | 2013 |
| Brickhill Tree Planting Ltd | Agriculture & fishing | 2024 |
| Bricknall's PC Services Ltd | Information & communication | 2020 |
| Brickpat Limited | Real estate | 2024 |
| Bricks and Mortgages Ltd | Financial services | 2018 |
| Bricks and Showers Ltd | Real estate | 2020 |
| Bricks Vision Limited | Real estate | 2024 |
| Brickway Limited | Construction | 2014 |
| Brickz Museum Limited | Arts & recreation | 2024 |
| Brickz Museum Trading Limited | Arts & recreation | 2024 |
| Bridevibe UK Ltd | Administrative & support | 2025 |
| Bridge Auto Centre Ltd | Wholesale & retail | 2024 |
| Bridge Autocare Limited | Wholesale & retail | 2019 |
| Bridge Burners Limited | Wholesale & retail | 2021 |
| Bridge Corp Limited | Administrative & support | 2025 |
| Bridge Inn Houses Ltd | Real estate | 2026 |
| Bridge IV Capital Limited | Professional & scientific | 2026 |
| Bridge Performance Ltd | Wholesale & retail | 2022 |
| Bridge Training Centre Ltd | Administrative & support | 2020 |
| BRIDGE2SUPPORT Ltd | Administrative & support | 2025 |
| Bridged 212 Ltd | Professional & scientific | 2025 |
| Bridgefast Imperial Limited | Professional & scientific | 2026 |
| Bridgeman Kettle LLP | | 2012 |
| Bridgenet. Bgnu Ltd | Information & communication | 2025 |
| Bridgeporth Ltd. | Professional & scientific | 2012 |
| Bridgeriver Holdings Ltd | Real estate | 2025 |
| Bridgethree Associates Ltd | Health & social care | 2014 |
| Bridgetroll Limited | | 1988 |
| Bridgeway Nutrition Ltd | Wholesale & retail | 2026 |
| Bridgeways Housing & Support CIC | Real estate | 2025 |
| Bridgman & Bridgman LLP | | 2006 |
| Bridian Property Limited | Real estate | 2026 |
| Bridlebright Limited | Financial services | 2004 |
| Brielle Healthcare Services Ltd | Health & social care | 2023 |
| Brierstone Birtle Limited | Construction | 2021 |
| Brigets Ltd | Wholesale & retail | 2019 |
| Briggsy's Carpentry and Building Services Ltd | Construction | 2024 |
| Briggsy's Property Ltd | Real estate | 2024 |
| Bright Africa Ltd | Wholesale & retail | 2025 |
| Bright BEE Recruitment Ltd | Administrative & support | 2018 |
| Bright Consultant Limited | Wholesale & retail | 2023 |
| Bright Executive Recruitment Limited | Administrative & support | 2000 |
| Bright Guys Enterprises Limited | Other services | 2026 |
| Bright Healthcare Provisionmk Ltd | Administrative & support | 2016 |
| Bright Healthcare Services Ltd | Administrative & support | 2009 |
| Bright RAY Solar Limited | Construction | 2025 |
| Bright Recruits Ltd | Administrative & support | 2023 |
| Bright Sparks Tuition Limited | Education | 2024 |
| Bright Spring Group Ltd | Wholesale & retail | 2019 |
| Bright.Blue UK Limited | Information & communication | 2022 |
| Bright.Express UK Ltd | Wholesale & retail | 2026 |
| Bright.Gold Platforms Limited | Information & communication | 2024 |
| Bright.Green Energy Limited | Information & communication | 2023 |
| Bright.People UK Limited | Administrative & support | 2024 |
| Bright.Space Media Limited | Professional & scientific | 2024 |
| Brightbee Trading Ltd | Construction | 2023 |
| Brightblessing Healthcare Ltd | Health & social care | 2020 |