| Brackmills Industrial Estate Limited | Other services | 2009 |
| Brad & Bent Property Rental Ltd | Real estate | 2022 |
| Bradbury Equity Investments Limited | Real estate | 2024 |
| Bradden Estates Management Ltd | Agriculture & fishing | 2009 |
| Bradfield JT Services Limited | Health & social care | 2025 |
| Bradford Bulls Northern Limited | Arts & recreation | 2007 |
| Bradford House (Management) Limited | Households | 1982 |
| Bradley Limited | Information & communication | 1992 |
| Bradzone Limited | Administrative & support | 2002 |
| Braid Retail Ltd | Professional & scientific | 2010 |
| Brain FUD Ltd | Manufacturing | 2016 |
| Brainport Limited | Administrative & support | 2004 |
| Braintree 10 Renewables Limited | Professional & scientific | 2023 |
| Braintree Residents Management Company Limited | Real estate | 2023 |
| Brainwaves Brain Health Ltd | Health & social care | 2026 |
| Bramble Tots Limited | Arts & recreation | 2025 |
| Bramley 2 Renewables Ltd | Professional & scientific | 2023 |
| Bramley 7 Renewables Ltd | Professional & scientific | 2023 |
| Brampton Care Solutions Ltd | Administrative & support | 2017 |
| Brampton Chase Flooring International Limited | Extraterritorial | 2020 |
| Brampton Chase Flooring Limited | Extraterritorial | 2020 |
| Brampton Electrical Services Limited | Construction | 2010 |
| Brampton Heath Golf Centre Ltd | Arts & recreation | 1979 |
| Brampton Holdings Ltd | Financial services | 2022 |
| Brampton Investments & Consulting Ltd | Financial services | 2018 |
| Brampton Management Company Limited | Real estate | 2002 |
| Brampton Parkhome Services UK Ltd | Administrative & support | 2013 |
| Brampton Property Investments and Management Ltd | Real estate | 2022 |
| Brampton Support Limited | Health & social care | 2024 |
| Brampton Valley (Brampton HUT) Limited | Administrative & support | 2014 |
| Brampton Valley Enterprises Ltd | Professional & scientific | 2024 |
| Brampton Valley Homes Limited | Real estate | 2016 |
| Brampton Valley Langley Mill Limited | Construction | 2010 |
| Brampton Valley Limited | Construction | 2002 |
| Brampton Valley Pineham Ltd | Construction | 2013 |
| Brampton Wealth Management Limited | Financial services | 2014 |
| Brand Connect Ltd | Wholesale & retail | 2019 |
| Brand Female Leadership Limited | Professional & scientific | 2026 |
| Brand K Holdings Ltd | Financial services | 2022 |
| Brand K Ltd | Financial services | 2018 |
| Branded Food Wraps Limited | Hospitality | 2013 |
| Brandedcommerce Ltd | Wholesale & retail | 2026 |
| Brandhouse Corporation Limited | Information & communication | 2013 |
| Branditpack Limited | Manufacturing | 2017 |
| Brandline Products Ltd | Wholesale & retail | 2009 |
| Brandon Media Limited | Information & communication | 2015 |
| Brandon Racing Limited | Arts & recreation | 2000 |
| Brandon Surveys Limited | Construction | 1986 |
| Brands in Distribution Ltd | Wholesale & retail | 2018 |
| Brandwise Retail Limited | Administrative & support | 1997 |
| Braniste Ltd | Construction | 2021 |
| Branson 4X4 Limited | Wholesale & retail | 2026 |
| Branson Mews Ltd | Households | 2012 |
| Braunston Home Improvements Limited | Professional & scientific | 2014 |
| Brave Brickwork Ltd | Construction | 2022 |
| Brave New World Publishing Limited | Information & communication | 2011 |
| Bravo Brick Ltd | Construction | 2020 |
| Bravo Construction Ltd | Construction | 2016 |
| Bray Hospitality Ltd | Hospitality | 2025 |
| BRC Construction Services Ltd | Administrative & support | 2023 |
| BRC Entertainment Limited | Information & communication | 2021 |
| BRD Calibration Ltd | Professional & scientific | 1999 |
| Breakthrough Community Speaking CIC | Administrative & support | 2024 |
| Breakx Group Ltd | Administrative & support | 2021 |
| Bredanny Concept Limited | Administrative & support | 2019 |
| Brelz International Ltd | Construction | 2021 |
| Breme Ltd | Wholesale & retail | 2026 |
| Bremont Bespoke Ltd | Construction | 2024 |
| Brendan Read Jones Limited | Information & communication | 2013 |
| Brenholly House Properties Ltd | Real estate | 2020 |
| Breth Limited | Arts & recreation | 2022 |
| Bretton Construction Limited | Construction | 2019 |
| Brew and Bite Hub Ltd | Hospitality | 2025 |
| Brewery Craft TAP Co Ltd | Hospitality | 2025 |
| Brewery Shades Company Limited | Hospitality | 2024 |
| Brewsolutionstech Limited | Information & communication | 2026 |
| BRG Roofing Limited | Construction | 2020 |
| BRI (Hitchin) Limited | Administrative & support | 2025 |
| BRI (Banbury) Limited | Extraterritorial | 2003 |
| BRI (Coventry) Limited | Administrative & support | 2003 |
| BRI (Milton Keynes) Limited | Administrative & support | 2003 |
| BRI (Northampton) Limited | Administrative & support | 2003 |
| BRI (UK) Limited | Administrative & support | 2000 |
| BRI (UK) Trustees Limited | Administrative & support | 2020 |
| Brian Bradshaw Motor Engineers Limited | Wholesale & retail | 2010 |
| Brian Meek Technical Services Limited | Manufacturing | 2014 |
| Brian Templar Associates Limited | Professional & scientific | 2024 |
| Brianacar Trans Limited | Other services | 2017 |
| Briche Ltd | Administrative & support | 2016 |
| Brick Flip Ltd | Wholesale & retail | 2022 |
| Brick Street Opco Limited | Real estate | 2014 |
| Brickforce Ltd | Construction | 2025 |
| Brickhill Mews Management Company Limited | Hospitality | 1989 |
| Brickids Ltd | Construction | 2026 |
| Brickmaster Works Ltd | Construction | 2024 |
| Brickndr Ltd | Construction | 2025 |
| Brickonmd Ltd | Construction | 2023 |
| Brickplans Construction Ltd | Construction | 2026 |
| Brickpoint Development Ltd | Real estate | 2018 |
| Brickpoint Investment Limited | Construction | 2019 |