| Bokst Ltd | Information & communication | 2021 |
| Bolt-On Digital Ltd | Information & communication | 2024 |
| BON BON Holdings Ltd | Administrative & support | 2018 |
| Boniti Ltd | Extraterritorial | 2007 |
| Bood Group Limited | Construction | 2023 |
| Book Ignition Ltd | Information & communication | 2019 |
| Books About Art Limited | Wholesale & retail | 2019 |
| Boole Crop Specialists Limited | Agriculture & fishing | 2016 |
| Boreray Ltd | Professional & scientific | 2018 |
| BOS FX Limited | Financial services | 2025 |
| Boston Food Services Limited | Hospitality | 2019 |
| Boughey Ltd | Transport & logistics | 2021 |
| Boundary Farm Business Park Ltd | Real estate | 2023 |
| Boundless Creations Limited | Professional & scientific | 2011 |
| Bowalicious Bows UK Limited | Manufacturing | 2024 |
| Bowen Accountants Holdings Ltd | Financial services | 2021 |
| Bowen Accountants Ltd | Professional & scientific | 2009 |
| Bowood Group Limited | Construction | 2011 |
| Bowood Lettings Ltd | Real estate | 2024 |
| Box and Seal Limited | Manufacturing | 2002 |
| Box Clever Productions Limited | Wholesale & retail | 2017 |
| Boxfields Limited | Hospitality | 2015 |
| Boxtop Technologies Limited | Information & communication | 1994 |
| Boxwood Productions Ltd | Financial services | 2024 |
| Bozas International Limited | Information & communication | 1994 |
| Bpclx Limited | Extraterritorial | 2010 |
| BPD Property Ltd | Transport & logistics | 2024 |
| Bracey Interiors Ltd | Wholesale & retail | 2003 |
| Bradfield Farm and Estate LLP | | 2026 |
| Bradfield Farms Limited | Agriculture & fishing | 1983 |
| Bradways Healthcare Limited | Health & social care | 2023 |
| Braeside House Limited | Education | 2019 |
| Brain Properties Bath Limited | Real estate | 2024 |
| Bramblekids Ltd | Information & communication | 2011 |
| Branch Walkers Tree Services Limited | Agriculture & fishing | 2002 |
| Brand Marketing Solutions Limited | Financial services | 2013 |
| Brandon Hill Ice Cream Limited | Wholesale & retail | 2024 |
| Branwin Lettings Limited | Real estate | 2018 |
| Brass Tacks Corporate Ltd | Professional & scientific | 2023 |
| Bravebid | Real estate | 1958 |
| Brelade Ventures Ltd | Financial services | 2021 |
| Bremhill Mowers Limited | Administrative & support | 2003 |
| Brendan Lynch Consulting Ltd | Administrative & support | 2015 |
| Bretton Holdings Limited | Financial services | 2018 |
| Brewberry Limited | Manufacturing | 2018 |
| Brian Abbott Training Limited | Administrative & support | 2011 |
| Brian R Allison Limited | Construction | 2003 |
| Brian Shaw (Colerne) Limited | Wholesale & retail | 2003 |
| Brian Shaw (Twerton) Limited | Wholesale & retail | 2003 |
| Briarwood Solutions Limited | Information & communication | 2010 |
| Bricks & Mortar Projects Limited | Construction | 2010 |
| Bridge Contract Solutions Limited | Manufacturing | 2012 |
| Bridger Ridge Consulting Limited | Professional & scientific | 2015 |
| Brief to Event Solutions Limited | Professional & scientific | 2005 |
| Bright Affect Limited | Information & communication | 2014 |
| Bright Buttons Education Limited | Education | 2025 |
| Bright Logistics Limited | Transport & logistics | 2021 |
| Bright's Village Store Ltd | Wholesale & retail | 2020 |
| Brignall Opticians Ltd | Wholesale & retail | 2012 |
| Brilliant Enterprises Limited | Information & communication | 2026 |
| Brinkworth Agriculture and Sheep Lodging Limited | Real estate | 2014 |
| Brinkworth Golf Club Ltd | Arts & recreation | 2019 |
| Bristol & Bath Heritage Consultancy Ltd | Professional & scientific | 2018 |
| Bristol Car Hire Ltd | Administrative & support | 2025 |
| Bristol Ice Cream Limited | Hospitality | 2018 |
| Brix Bistro Limited | Hospitality | 2012 |
| BRO Homes Ltd | Real estate | 2021 |
| Broad Street Asset Management Ltd | Financial services | 2018 |
| Brockley Nurseries Development Co Ltd | Construction | 2023 |
| Broduil Limited | Information & communication | 2022 |
| Bromham Community Enterprises Limited | Extraterritorial | 2025 |
| Bromham Growers Limited | Manufacturing | 1996 |
| Bronzeport Limited | Information & communication | 2011 |
| Brooke Turfrey Ltd | Wholesale & retail | 2019 |
| Brooklyn Developments Limited | Construction | 2003 |
| Brookman Greene Ltd | Other services | 2019 |
| Brookside Consultancy Limited | Professional & scientific | 2022 |
| Brookside Glazing Ltd | Wholesale & retail | 2024 |
| Brother From Another Ltd | Arts & recreation | 2017 |
| Brother From Another Productions Limited | Arts & recreation | 2024 |
| Brown's Woodworking Limited | Manufacturing | 2003 |
| Browns Beauty (Bath) Limited | Other services | 2018 |
| BRR Consulting Limited | Professional & scientific | 2012 |
| Brunel Microscopes Limited | Professional & scientific | 1986 |
| BS3 Private Ltd | Real estate | 2023 |
| BSH Carpentry Limited | Construction | 2019 |
| Bspc Holdings Limited | Real estate | 2019 |
| BSW Power EU Ltd | Administrative & support | 2016 |
| BTE Resins Limited | Administrative & support | 2020 |
| Btps Partnership (Chippenham) Limited | Administrative & support | 2013 |
| Buchan Investments Limited | Financial services | 1998 |
| Buckleylettings Ltd | Real estate | 2025 |
| Buddyfied Limited | Extraterritorial | 2009 |
| Bugerdvws Ltd | Wholesale & retail | 2024 |
| Building Design Surveys Ltd | Construction | 2014 |
| Buildplans Limited | Professional & scientific | 2011 |
| Built Environment Solutions Limited | Extraterritorial | 2017 |
| Bulldog Bouncers Ltd | Arts & recreation | 2022 |
| Bulldog Consultants Limited | Information & communication | 2020 |
| Bullwren Ltd | Wholesale & retail | 2025 |