| Build Four Four Limited | Construction | 2024 |
| Builders Link Ltd | Professional & scientific | 2025 |
| Building Services BSE Ltd | Real estate | 2024 |
| Buildout Techno Limited | Professional & scientific | 2025 |
| Built Right Consulting Ltd | Professional & scientific | 2025 |
| Bulben House Limited | Wholesale & retail | 2018 |
| Bulgarian Cultural Community UK CIC | Real estate | 2024 |
| Bulkpot Ltd | Wholesale & retail | 2025 |
| Bull Barrier Limited | Manufacturing | 2015 |
| Bumble and Bloom Ltd | Wholesale & retail | 2026 |
| Bunbury Bookkeeping Ltd. | Professional & scientific | 2014 |
| Bunfluff Ltd | Manufacturing | 2023 |
| Buntings Developments Limited | Real estate | 2014 |
| Burbage Car Sales Ltd | Wholesale & retail | 2019 |
| Burford Reach Management Company Limited | Households | 1988 |
| Burg Group Ltd | Information & communication | 2025 |
| Burland Technology Solutions Limited | Wholesale & retail | 2007 |
| Burlingham Mill Management Limited | Households | 2023 |
| Burnett Barker Solicitors Limited | Professional & scientific | 2015 |
| Burnett Joel Ltd | Real estate | 2019 |
| Burrafirth Consulting Limited | Information & communication | 2024 |
| Burroughs Electrical Ltd | Construction | 2022 |
| Burst Networks Ltd | Information & communication | 2017 |
| Burst Studio Ltd | Professional & scientific | 2022 |
| Burt Bookkeeping Limited | Professional & scientific | 2018 |
| Burthorpe Accountants Limited | Professional & scientific | 2025 |
| Burthorpe Limited | Real estate | 2021 |
| Burthorpe Properties Limited | Real estate | 2024 |
| Burton & Co Solutions Ltd | Real estate | 2023 |
| Burton Developments Limited | Real estate | 2025 |
| Bury Bar Services Limited | Hospitality | 2011 |
| Bury Contractors Limited | Construction | 2021 |
| Bury Film Group CIC | Information & communication | 2024 |
| Bury Fish Ltd | Hospitality | 2025 |
| Bury Language School Property Limited | Real estate | 2014 |
| Bury Nail Spa and Beauty Ltd | Other services | 2025 |
| Bury Plumbing and Heating Ltd | Construction | 2022 |
| Bury ST Edmunds Academy Trust | Education | 2011 |
| Bury ST Edmunds Business Exchange CIC | Other services | 2026 |
| Bury ST Edmunds Heritage Trust | Arts & recreation | 2006 |
| Bury ST Edmunds Islamic Cultural Organisation | Other services | 2014 |
| Bury ST Edmunds IT Limited | Information & communication | 2021 |
| Bury ST Edmunds Taxi Ltd | Transport & logistics | 2024 |
| Bury ST Edmunds Travel Ltd | Transport & logistics | 2025 |
| Bury ST Edmunds Veterinary Centre Ltd | Professional & scientific | 2019 |
| Bury ST. Edmunds Women's AID Centre Limited | Health & social care | 1977 |
| Bury St.Edmunds Theatre Management Limited(The)(The) | Arts & recreation | 1965 |
| Bury Storage Products Limited | Professional & scientific | 2014 |
| Bury Town Football Club (1995) Limited | Arts & recreation | 1995 |
| Bury Travel Limited | Transport & logistics | 2013 |
| Bury Turfcare Limited | Administrative & support | 2002 |
| Bury Vapeology Ltd | Wholesale & retail | 2026 |
| Bus&Truck Engineering Ltd | Wholesale & retail | 2024 |
| Business Development Solutions Limited | Information & communication | 2004 |
| Business Growth Coaches (Cambs) Ltd | Professional & scientific | 2018 |
| Business Growth People Limited | Financial services | 2018 |
| Business Growth Studios Ltd | Professional & scientific | 2022 |
| Business Launch Limited | Wholesale & retail | 2002 |
| Business Management Consultants Limited | Professional & scientific | 2003 |
| Business Marketer Ltd | Wholesale & retail | 2019 |
| Business Matters (Cheshire) Limited | Professional & scientific | 2025 |
| Business Rates Check Ltd | Administrative & support | 2025 |
| Business Studies Marketing Limited | Professional & scientific | 2023 |
| Business World TR Limited | Wholesale & retail | 2024 |
| Busy BEE Montessori Nursery School Limited | Education | 2002 |
| Busy Busy Learning Limited | Wholesale & retail | 2024 |
| Busy Clinic Ltd | Other services | 2023 |
| Butcher Property Investors Limited | Real estate | 2025 |
| Butter Drop Bakery Limited | Manufacturing | 2025 |
| Buuk Infrastructure Holdings Limited | Professional & scientific | 2012 |
| Buuk Infrastructure Issuer PLC | Professional & scientific | 2012 |
| Buuk Infrastructure Limited | Financial services | 2005 |
| Buuk Infrastructure NO 1 Limited | Professional & scientific | 2012 |
| Buuk Infrastructure NO 2 Limited | Professional & scientific | 2012 |
| Buxton Asset Management Ltd | Administrative & support | 2021 |
| Buy Drop Trade Ltd | Wholesale & retail | 2026 |
| Buy the Light Ltd | Wholesale & retail | 2011 |
| Buyer MAX Store Ltd | Wholesale & retail | 2023 |
| Buysellmodel Limited | Wholesale & retail | 2026 |
| Buysquad Ltd | Wholesale & retail | 2025 |
| Buywest Limited | Wholesale & retail | 2026 |
| Buzz Creator Ltd | Information & communication | 2015 |
| Buzz IT Services Limited | Extraterritorial | 2025 |
| Buzzards and Worms CIC | Administrative & support | 2024 |
| Buzzoni Ltd | Manufacturing | 2021 |
| BW Global Consulting Ltd | Professional & scientific | 2025 |
| Bwcompany Investments (Bwci) Limited | Professional & scientific | 2012 |
| BXC Facilities & Group Limited | Information & communication | 2026 |
| BY Destiny Pinto Ltd | Manufacturing | 2025 |
| BY Furniture Ltd | Wholesale & retail | 2025 |
| BY Ishq PVT. Ltd | Wholesale & retail | 2025 |
| BY JR Ltd | Health & social care | 2022 |
| BY KDM Ltd | Wholesale & retail | 2026 |
| Bylark Ltd | Real estate | 2018 |
| Bymead Properties Limited | Real estate | 2016 |
| Byrony Consulting Limited | Information & communication | 2016 |
| Bytebox Media Limited | Information & communication | 2021 |
| Bytelynk Solution Ltd | Information & communication | 2026 |
| Byteoxide Limited | Information & communication | 2023 |
| C & G Waters Investments Ltd | Construction | 2016 |