| BG Sports and Corporate Wear Limited | Wholesale & retail | 2016 |
| BH & DL Limited | Other services | 2020 |
| BH Assist Ltd | Administrative & support | 2025 |
| Big Bede Limited | Extraterritorial | 2024 |
| Biggs Fish Limited | Wholesale & retail | 2020 |
| Bigs Burgers Ltd | Hospitality | 2024 |
| Bio-Based and Biodegradable Industries Association (Bbia) Ltd | Other services | 2015 |
| Birchwood Estates Limited | Real estate | 2022 |
| Birmingham 247 Limited | Arts & recreation | 2021 |
| BJC Marine Limited | Professional & scientific | 2026 |
| BK Rogers Limited | Manufacturing | 2012 |
| Black & Wight Property Limited | Real estate | 2021 |
| Black COW Engineering Ltd | Professional & scientific | 2006 |
| Black Dog Medical Group Limited | Education | 2024 |
| Blackfriars Court Management Company Limited | Extraterritorial | 2012 |
| Blackwood Design Limited | Information & communication | 2010 |
| Blade Training Academy Ltd | Education | 2025 |
| Blakes Close RTM Company Limited | Households | 2019 |
| Blinds Plus Limited | Manufacturing | 2014 |
| Block Automotive Ltd | Professional & scientific | 2016 |
| Blocks Publishing Ltd | Information & communication | 2021 |
| Blue Giraffe Properties Limited | Real estate | 2016 |
| Blundeston House Farm Ltd | Agriculture & fishing | 2019 |
| BLW Fabrication Limited | Construction | 2025 |
| BM Davison Limited | Construction | 2009 |
| BM Electrical Services Ltd | Construction | 2025 |
| BMM Investment Ltd | Real estate | 2023 |
| BMZ Property Ltd | Real estate | 2020 |
| Bncn Business Solutions Ltd | Wholesale & retail | 2019 |
| Boathouse Pirates Ltd | Real estate | 2018 |
| Boild Mall Limited | Wholesale & retail | 2026 |
| Bolton Bluebells Limited | Administrative & support | 2018 |
| Bombshell Games Ltd | Information & communication | 2019 |
| Bombshell Studios Ltd | Professional & scientific | 2020 |
| Boogie the Rigbuilder Limited | Construction | 2014 |
| Botanico Limited | Wholesale & retail | 2018 |
| Bowden Environmental Consultancy Limited | Water & waste | 2017 |
| Box Offers Ltd | Wholesale & retail | 2024 |
| Brad Harrison Designs Ltd | Professional & scientific | 2022 |
| Braltu Ltd | Real estate | 2026 |
| Brand Welding Limited | Professional & scientific | 2021 |
| Brassway Limited | Administrative & support | 1994 |
| Breezeyrugs Limited | Manufacturing | 2025 |
| Breitling Homes Limited | Real estate | 2007 |
| Brennan Construction Limited | Construction | 2021 |
| Brett's Management Limited | Real estate | 2023 |
| Brian Alabaster Limited | Arts & recreation | 2002 |
| Bricked Bouquet Ltd | Wholesale & retail | 2024 |
| Bridge Road Store Ltd | Wholesale & retail | 2025 |
| Bridgecraft Limited | Manufacturing | 2003 |
| Brighter Move Maintenance Limited | Real estate | 2020 |
| Briscotec Ltd | Mining & quarrying | 2010 |
| Britesites Business Intelligence Limited | Information & communication | 2023 |
| Britten House (Lowestoft) Limited | Hospitality | 2011 |
| Broad Roots CIC | Education | 2023 |
| Broadholme Management Company Ltd | Real estate | 2020 |
| Broadland Access Training Limited | Professional & scientific | 2014 |
| Broadland Court Limited | Households | 1985 |
| Broadland Memorials Limited | Financial services | 2016 |
| Broadland Plumbing and Heating Limited | Construction | 2024 |
| Broadland Real Estate Limited | Real estate | 2016 |
| Broadview Electrical Company Limited | Construction | 2003 |
| Brock Brothers Builders Limited | Construction | 1965 |
| Brock Builders (Kessingland) Limited | Construction | 1981 |
| Brock FMD Limited | Construction | 1996 |
| Brooke Marine Ltd | Manufacturing | 2020 |
| Brownline UK Ltd | Administrative & support | 2024 |
| Browston Hall Golf & Leisure Limited | Hospitality | 2003 |
| Browston Hall Holdings Ltd | Financial services | 2017 |
| Buckingham QA Consultancy Limited | Administrative & support | 2003 |
| Budget Finance Flooring Ltd | Construction | 2025 |
| Build Customz Ltd | Wholesale & retail | 2025 |
| Buildfix Limited | Real estate | 1995 |
| Bullard & Sons Ltd | Extraterritorial | 2015 |
| Bullard Wealth Limited | Financial services | 2016 |
| Bullards Brewery Ltd | Extraterritorial | 2015 |
| Bulldog Plant Ltd | Manufacturing | 2021 |
| Bullnet Services Limited | Wholesale & retail | 2019 |
| Bunders Media Ltd | Information & communication | 2022 |
| Bungay & Waveney Valley Golf Club Limited | Arts & recreation | 2019 |
| Buraq Marine Limited | Other services | 2025 |
| Burdikin Investments Ltd | Real estate | 2017 |
| Bury Design Services Limited | Extraterritorial | 1981 |
| Buyaparcel Limited | Financial services | 2014 |
| Buyaparcel Trustee Limited | Other services | 2024 |
| Buzzards Retreat Limited | Construction | 2019 |
| BWS Services Ltd | Professional & scientific | 2019 |
| C & R Consultants LLP | | 2003 |
| C and a Builders Anglia Limited | Construction | 2019 |
| C E Aviation UK Limited | Transport & logistics | 2009 |
| C E Property Holdings Limited | Real estate | 2015 |
| C G Gamson Limited | Professional & scientific | 2021 |
| C Goodings Plumbing & Heating Ltd | Construction | 2021 |
| C K Farms Limited | Agriculture & fishing | 1997 |
| C Loghin Catering Limited | Hospitality | 2019 |
| C R Hales Limited | Water & waste | 1991 |
| C R Hales Property Limited | Extraterritorial | 2013 |
| C S Contracts Anglia Ltd | Construction | 2024 |
| C S H Property Limited | Real estate | 2002 |
| C Wood Hospitality Limited | Hospitality | 2017 |