| Board Level Jobs Ltd | Administrative & support | 2011 |
| BOB Loydall Mortgages Limited | Financial services | 2015 |
| Bobble Creative Limited | Professional & scientific | 2019 |
| Boben & Co. Limited | Construction | 2015 |
| Boben Construction Limited | Extraterritorial | 2022 |
| Bodo RIM Limited | Mining & quarrying | 2019 |
| Bogdan JOB Done Limited | Transport & logistics | 2012 |
| Bogisun Trade Limited | Transport & logistics | 2008 |
| Bolskaf Ltd | Wholesale & retail | 2026 |
| Bonz-Ai Limited | Information & communication | 2025 |
| Bookanengineer Limited | Information & communication | 2002 |
| Books and Goods Ltd | Wholesale & retail | 2023 |
| Bookwarmbay Ltd | Information & communication | 2025 |
| Boomi Consultancy Ltd | Real estate | 2022 |
| Boomslang Investments Limited | Real estate | 2019 |
| Boost on Ltd | Wholesale & retail | 2024 |
| Boots Farm Holdings Limited | Financial services | 2024 |
| Boots Farm Limited | Real estate | 2024 |
| Boots N Boogie Ltd | Education | 2026 |
| Bosanko Engineering Limited | Manufacturing | 2004 |
| Boss Photobooths & Entertainments Ltd | Professional & scientific | 2020 |
| Bosworth Developments Ltd | Real estate | 2024 |
| Bosworth Land & Property Limited | Real estate | 2023 |
| Boult Bros. (Properties) Ltd | Real estate | 2006 |
| Bourchier Contracting Ltd | Manufacturing | 2025 |
| Boutique (York) Limited | Hospitality | 2005 |
| BOW Communications Limited | Information & communication | 1995 |
| BOW Legged Leisure Limited | Hospitality | 2017 |
| Bowen Marine Associates Ltd | Manufacturing | 2011 |
| Bowie Lockwood Structures Limited | Manufacturing | 1995 |
| Boymans Ltd | Transport & logistics | 2017 |
| Bozkurt Coffee Limited | Hospitality | 2024 |
| BP Property Solutions Ltd | Real estate | 2019 |
| BP Surveys Ltd | Professional & scientific | 2021 |
| Bpss Abode UK Ltd | Real estate | 2024 |
| Bpss Consulting Ltd | Professional & scientific | 2025 |
| BR Amazon Ltd | Wholesale & retail | 2024 |
| Bradby Gardens Management Limited | Real estate | 2019 |
| Bradley Adams Bedrooms Limited | Manufacturing | 2004 |
| Bradley Electrical Limited | Construction | 2012 |
| Bradley Morgan Commercial Services Ltd | Wholesale & retail | 2022 |
| Bradshaw Trading Ltd | Wholesale & retail | 2021 |
| Braich Limited | Wholesale & retail | 1998 |
| Brain Power Industries Limited | Manufacturing | 1996 |
| Brain Power International Limited | Manufacturing | 1984 |
| Brainy Ltd. | Other services | 2015 |
| Brambles (Warwickshire) Ltd | Agriculture & fishing | 2014 |
| Bran IT Services Ltd | Information & communication | 2024 |
| Branchard Tree & Landscapes Services Ltd | Agriculture & fishing | 2026 |
| Brand Consultancy (Services) Limited | Professional & scientific | 2013 |
| Brandish Limited | Wholesale & retail | 2002 |
| Brandon Thatchers Film Services Limited | Information & communication | 2014 |
| Brandyd by LYD Ltd | Professional & scientific | 2023 |
| Braxton Works Ltd | Real estate | 2024 |
| Brayford Estates Limited | Real estate | 2010 |
| BRD Telecoms Ltd | Professional & scientific | 2023 |
| Breachwood Transport & Removals Limited | Transport & logistics | 1962 |
| Breakwater Cottages Ltd | Hospitality | 2024 |
| Bremer Engineering Company Limited | Manufacturing | 2017 |
| Brethertons LLP | | 2006 |
| Brett Eagan Paving Ltd | Construction | 2021 |
| Brews & Bites Bistro Ltd | Hospitality | 2023 |
| Brezin Ltd | Wholesale & retail | 2020 |
| Brian James Trailers Holdings Limited | Professional & scientific | 2017 |
| Brian James Trailers Limited | Manufacturing | 1999 |
| Brian MCG Real Estate Ltd | Real estate | 2021 |
| Brian Owen Consultancy Limited | Professional & scientific | 2019 |
| Brian Owen Limited | Professional & scientific | 2006 |
| Brian Owen Personal Taxation Limited | Professional & scientific | 2016 |
| Briar and Bard Drinks Company Limited | Manufacturing | 2025 |
| Brice Electrical Limited | Construction | 2026 |
| Brice Environmental Services Ltd. | Water & waste | 2003 |
| Brick Box Enterprises Ltd | Real estate | 2020 |
| Brickhill Logistics Limited | Transport & logistics | 2017 |
| Bridge ARK Partners Ltd | Construction | 2024 |
| Bridge Newland Limited | Administrative & support | 2011 |
| Bridge-It Advisory Services Ltd | Professional & scientific | 2010 |
| Bridle Consulting Engineers Limited | Other services | 2001 |
| Bright Art Creative Ltd | Education | 2026 |
| Bright Sky Laundry Services Ltd | Other services | 2008 |
| Brighter Windows Limited | Construction | 2012 |
| Brihome Limited | Wholesale & retail | 2017 |
| Brilliant Emerald Productions Limited | Information & communication | 2006 |
| Brindavanam Limited | Real estate | 2022 |
| Brindlestore Limited | Professional & scientific | 2018 |
| Brinklow Skips and Recycling Limited | Construction | 2016 |
| Briorocks Limited | Other services | 2020 |
| Brisel Ltd | Information & communication | 2016 |
| British Speedway Promoters Limited | Arts & recreation | 2019 |
| British Tamil Language Examination Board CIC | Public administration | 2024 |
| Britlon Consultancy Ltd | Information & communication | 2016 |
| Britmade Limited | Extraterritorial | 1997 |
| Britspace UK Ltd | Wholesale & retail | 2026 |
| Britterra Properties Ltd | Real estate | 2025 |
| Brixham Barbershop Limited | Other services | 2014 |
| Broad Street Securities Limited | Extraterritorial | 1977 |
| Broadoak Mechanical Design Limited | Administrative & support | 2007 |
| Broadslade Properties Limited | Real estate | 2017 |
| Broklyn Barber Ltd | Other services | 2023 |
| Bronte Close Community Garden CIC | Agriculture & fishing | 2021 |