| Barn Key Ltd | Real estate | 2025 |
| Barnaby & Jones Ltd | Extraterritorial | 2020 |
| Barnsley Great Superstore Ltd | Wholesale & retail | 2019 |
| Baron JAY Limited | Manufacturing | 1973 |
| Bartlett Holmes Building Services Ltd | Real estate | 2003 |
| Bartletts Supervision Limited | Transport & logistics | 2015 |
| Barton Cooling Services Ltd | Construction | 2022 |
| Barton Garden Maintenance Ltd | Administrative & support | 2025 |
| Barton Hall Farm Management Company Limited | Real estate | 2008 |
| Barton Landscapes Construction Ltd | Construction | 2023 |
| Barton Landscapes Limited | Administrative & support | 2012 |
| Bartorelli Ltd | Manufacturing | 2011 |
| Barwhale Holdings Ltd | Administrative & support | 2019 |
| Baskervilles (Ashburton) Ltd | Professional & scientific | 2016 |
| Bathroom Panels Direct Ltd | Wholesale & retail | 2024 |
| Battersby Arnold LLP | | 2024 |
| Batts Equestrian Limited | Agriculture & fishing | 2020 |
| Baxhp Holdings Ltd | Financial services | 2023 |
| Baxter & Miller Limited | Hospitality | 2015 |
| Bay Photonics Ltd | Manufacturing | 2007 |
| Bay Tree Catering Limited | Wholesale & retail | 2007 |
| Bay View Hotels Limited | Hospitality | 2011 |
| Baymoor Interiors Ltd | Administrative & support | 2017 |
| Bayside Cleaning Services Ltd | Water & waste | 2023 |
| Bayside Graphics Limited | Professional & scientific | 2015 |
| Baytor (Property Services) Limited | Construction | 2004 |
| Baytor Holdings Limited | Financial services | 2025 |
| Baytree & Mcqueen Limited | Manufacturing | 2022 |
| BBA Aerial Photographics Limited | Professional & scientific | 2010 |
| BBB Fishing Limited | Agriculture & fishing | 2022 |
| BCG (Retail) Limited | Wholesale & retail | 1988 |
| Bcom Ltd | Financial services | 2018 |
| BDD Scaffolding Limited | Construction | 2018 |
| BE Happy at Home Limited | Health & social care | 2023 |
| BE More Shark Ltd | Professional & scientific | 2024 |
| BE World Class Education Ltd | Information & communication | 2023 |
| Beach Lapidary Limited | Manufacturing | 2022 |
| Beachcomber Magazines Ltd | Information & communication | 2005 |
| Beachwood Bakery Ltd | Wholesale & retail | 2019 |
| Beacon Strategic Communications Limited | Professional & scientific | 2001 |
| Beadon Consulting Ltd | Professional & scientific | 2023 |
| Beara Holdings Ltd | Financial services | 2023 |
| Beara Investments Limited | Real estate | 1973 |
| Bearded Creative Studio Limited | Professional & scientific | 2020 |
| Bearhug Marketing and Communications Ltd | Professional & scientific | 2025 |
| Bedish Artisan Foods Ltd | Hospitality | 2019 |
| Bedrock Systems Limited | Information & communication | 2015 |
| Beds (SW) 2023 Limited | Financial services | 2023 |
| Bedstraw and Madder Limited | Manufacturing | 2018 |
| Beenbo&Co Limited | Manufacturing | 2022 |
| Beer in the Hand Ltd | Wholesale & retail | 2023 |
| Bees Houses LLP | | 2024 |
| Bellacouche Ltd | Manufacturing | 2024 |
| Bellaford Medical Services Limited | Health & social care | 2012 |
| Bellaford Property Services Limited | Real estate | 2019 |
| Bellas Consultancy Ltd | Professional & scientific | 2018 |
| Bellhurst Limited | | 1973 |
| Belvedere Consulting (Southwest) Ltd | Professional & scientific | 2025 |
| Belvedere Products Ltd | Manufacturing | 2005 |
| Belvedere Roofs Ltd | Manufacturing | 2019 |
| Belvedere Vantage Limited | Professional & scientific | 2005 |
| BEN Bradley HIP and Knee Limited | Health & social care | 2021 |
| BEN Bradstock Limited | Agriculture & fishing | 2018 |
| BEN Davis Plumbing & Heating Ltd | Construction | 2020 |
| BEN Jones Limited | Real estate | 2010 |
| BEN Todd Plumbing and Heating Ltd | Construction | 2019 |
| BEN TOM Services Ltd | Information & communication | 2026 |
| Benbow Group Holdings Limited | Financial services | 2018 |
| Benbow Interiors Limited | Manufacturing | 1995 |
| Benbow Trustees Limited | Other services | 2022 |
| Bennah Limited | Real estate | 1927 |
| Bergamo Capital Ltd | Professional & scientific | 2023 |
| Bergman Homes (Devon) Ltd | Real estate | 2021 |
| Berry Castle Shoot Limited | Arts & recreation | 2016 |
| Berry's Decorating Centre Limited | Wholesale & retail | 2016 |
| Berserks Glass Works Ltd | Manufacturing | 2011 |
| Berto's Pizza Restaurant Ltd | Hospitality | 2021 |
| Bespoak Designs Ltd | Manufacturing | 2012 |
| Bespoke Baby Box Ltd | Other services | 2020 |
| Bespoke Craftsmen Limited | Construction | 2017 |
| Best Accountancy Services (Newton Abbot) Ltd | Professional & scientific | 2014 |
| Besthaus Ltd | Real estate | 2024 |
| Bestway Corp UK Limited | Wholesale & retail | 2020 |
| Bethan View Management Company Limited | Households | 2013 |
| Beverley Rise Limited | Real estate | 2024 |
| BEW Medical Limited | Health & social care | 2024 |
| Bi-Zen Limited | Information & communication | 2016 |
| Biblehaus Limited | Extraterritorial | 2014 |
| Biblehaus Publishing Limited | Extraterritorial | 2014 |
| BIC Solutions Limited | Professional & scientific | 2004 |
| Bickington Goodwill Community CIC | Health & social care | 2023 |
| Bickington Limited | Hospitality | 1994 |
| Bickington Village Trust Limited | Health & social care | 2006 |
| Big BOY London Ltd | Wholesale & retail | 2016 |
| Big Fish Concepts Ltd | Information & communication | 2010 |
| Big Heat Ltd | Construction | 2025 |
| Big Noise Music Factory CIC | Information & communication | 2025 |
| Bigpeaks.Com Limited | Wholesale & retail | 2000 |
| BIJ Consulting Limited | Professional & scientific | 2023 |
| Bikini Lists Limited | Information & communication | 1999 |