| Break Into Snooker Ltd | Information & communication | 2025 |
| Breakthrough Education Support Limited | Education | 2013 |
| Breathe Solutions Group Limited | Professional & scientific | 2018 |
| Breathe Technologies Ltd | Information & communication | 2009 |
| Brecon Power Ltd | Energy | 2014 |
| Bred Consultants Ltd | Professional & scientific | 2019 |
| Bree Holdings Limited | Financial services | 2026 |
| Breen Enterprises Ltd | Transport & logistics | 2020 |
| Breezr Limited | Wholesale & retail | 2019 |
| Bren Clad Limited | Construction | 2021 |
| Brendan Anderson Consulting Ltd | Administrative & support | 2024 |
| Brendon Construction Ltd | Construction | 2019 |
| Brennan Consultancy Limited | Administrative & support | 2025 |
| Brennan Electrical Solutions Limited | Construction | 2024 |
| Brennslan Property Investments Limited | Real estate | 2026 |
| Brennslan Property Sourcing Limited | Real estate | 2026 |
| Brentham Consulting Limited | Information & communication | 2016 |
| Brentwood Commissioning Services Ltd | Professional & scientific | 2019 |
| Brentwood Sustainability Limited | Professional & scientific | 2022 |
| Brett Madden & SON Limited | Administrative & support | 2013 |
| Brew 13 Services Limited | Administrative & support | 2016 |
| Brewco CWL Limited | Hospitality | 2024 |
| Brian Harrison Civil Engineering Limited | Professional & scientific | 2018 |
| Brian Maclennan Quality Services Limited | Administrative & support | 2007 |
| Briar & Gill Limited | Administrative & support | 2015 |
| Briar CAD Solutions Limited | Administrative & support | 2021 |
| Briar Dene Homes Ltd | Real estate | 2025 |
| Briars Accounts Ltd | Extraterritorial | 1998 |
| Briarwood Business Services Limited | Professional & scientific | 2016 |
| Briarwood Productions Limited | Wholesale & retail | 2022 |
| Bricklayer With Mason Ltd | Construction | 2020 |
| Bricks Management Ltd | Real estate | 2019 |
| Brics Housing Limited | Real estate | 2024 |
| Bridge 71 Ltd | Hospitality | 2024 |
| Bridge Drawing Solutions Limited | Administrative & support | 2008 |
| Bridge Lane Stores Ltd | Wholesale & retail | 2024 |
| Bridge Link UK Properties and Letting Limited | Real estate | 2022 |
| Bridge Point Media Ltd | Professional & scientific | 2025 |
| Bridge Road (Warrington) Limited | Real estate | 2021 |
| Bridge Street Investments Limited | Real estate | 2022 |
| Bridge Street Property Holdings Limited | Real estate | 2025 |
| Bridgefoot Bodyshop Limited | Transport & logistics | 2020 |
| Bridgefoot Recovery Limited | Transport & logistics | 2025 |
| Bridgemind Health Ltd | Information & communication | 2026 |
| Bridgen Consultancy Ltd | Information & communication | 2026 |
| Bridger Solutions Ltd | Professional & scientific | 2025 |
| Bridgewater & Sons Limited | Construction | 2012 |
| Bridgewater Day Care Ltd | Health & social care | 2013 |
| Bridgewater Investment Group Ltd | Financial services | 2024 |
| Bridgewater Mews Projects Limited | Professional & scientific | 2018 |
| Bridgewater Projects M33 Ltd | Construction | 2021 |
| Bridgewater Property Assets Ltd | Construction | 2024 |
| Brigantium Engineering Limited | Professional & scientific | 2018 |
| Briggs Landscaping Ltd | Administrative & support | 2026 |
| Bright Consulting Partners Ltd | Information & communication | 2023 |
| Bright Hill Technical Solutions Limited | Information & communication | 2017 |
| Bright Housing Partners Ltd | Real estate | 2025 |
| Bright Voices Speech Therapy Ltd | Health & social care | 2026 |
| Bright `N` Trendy Limited | Information & communication | 2008 |
| Brighter Business Consulting Ltd | Professional & scientific | 2023 |
| BRIGHTER2GETHER Community Interest Company | Education | 2024 |
| Brighton and Sussex Care Limited | Health & social care | 2010 |
| Brightspark Retail Ltd | Wholesale & retail | 2025 |
| Brijan Engineering Services Limited | Administrative & support | 2014 |
| Brim Engineering Ltd | Administrative & support | 2024 |
| Brin Studios Ltd | Professional & scientific | 2024 |
| Brinny Does Ltd | Professional & scientific | 2023 |
| Bristol & West Financial Services Limited | Administrative & support | 2014 |
| Brit- Lube Ltd | Wholesale & retail | 2007 |
| Brit-Tipp Limited | Manufacturing | 1983 |
| Brit-Tipp TM Ltd | Manufacturing | 2023 |
| British Engineering Inspection Services Limited | Professional & scientific | 2016 |
| British Engineering Services Asset Reliability Limited | Professional & scientific | 2003 |
| British Engineering Services Asset Reliability Mimic Limited | Information & communication | 2003 |
| British Engineering Services Asset Reliability Strainstall Limited | Manufacturing | 2000 |
| British Engineering Services Bidco Limited | Financial services | 2020 |
| British Engineering Services Finco 1 Limited | Financial services | 2020 |
| British Engineering Services Holdco Limited | Professional & scientific | 2015 |
| British Engineering Services Limited | Professional & scientific | 2014 |
| British Engineering Services Midco Ltd. | Financial services | 2020 |
| British Engineering Services Topco 1 Limited | Financial services | 2020 |
| Britney Beeby Creative Limited | Arts & recreation | 2019 |
| Britplas (EOT) Limited | Financial services | 2024 |
| Britplas Commercial Limited | Construction | 2006 |
| Britplas Fabrications Limited | Manufacturing | 1995 |
| Britplas Facades Limited | Construction | 2015 |
| Britplas Group Limited | Financial services | 2019 |
| Brix Group Ltd | Financial services | 2023 |
| BRL Energy Ltd | Energy | 2024 |
| Broad Access Services Ltd | Information & communication | 2019 |
| Broadoaks Service Station Limited | Wholesale & retail | 1986 |
| Brocklehurst Flooring Ltd | Construction | 2015 |
| Brocklehurst Ltd | Construction | 2019 |
| Brockton Court Management Limited | Households | 1976 |
| Brokaitis Services Limited | Administrative & support | 2014 |
| Bromford Limited | Information & communication | 2019 |
| Bromilow Property Surveyors Ltd | Professional & scientific | 2022 |
| Bromley Tyres Limited | Wholesale & retail | 2007 |
| Bromwich ST. Management Co. Limited | Real estate | 2004 |
| Brook & Lands Ltd | Administrative & support | 2026 |