| B & I Properties Limited | Financial services | 2011 |
| B & J Contracting Services Limited | Construction | 2001 |
| B & L Business Limited | Administrative & support | 2008 |
| B Bull Limited | Financial services | 2021 |
| B Living Group Limited | Real estate | 2026 |
| B Russell External Rendering Limited | Construction | 2006 |
| B&A Vans Limited | Wholesale & retail | 2022 |
| B&M Joinery (Chippenham) Limited | Manufacturing | 2005 |
| B&W Elite Juniors Kickboxing Ltd | Arts & recreation | 2024 |
| B.T.F.P. Limited | Extraterritorial | 2010 |
| B2 Building Services Ltd | Construction | 1994 |
| B2E Square Events Management Limited | Administrative & support | 2008 |
| B3 Construction Limited | Construction | 2021 |
| B3 Homes (Esher) Ltd | Extraterritorial | 2020 |
| B3 Homes (Hartley) Limited | Real estate | 2021 |
| B3 Homes (Warlingham) Ltd | Real estate | 2024 |
| B3 Homes Development Limited | Real estate | 2021 |
| B3 Homes Group Ltd | Financial services | 2017 |
| B3 Homes Ltd | Real estate | 2021 |
| Babs Healthcare Solutions Ltd | Health & social care | 2020 |
| Babs Real Estate Ltd | Real estate | 2020 |
| Backdrop Education Services Ltd | Education | 2016 |
| Bahdaf Ltd | Extraterritorial | 2023 |
| Bailey Business Ltd | Construction | 2021 |
| Bailey Construction South West Ltd | Construction | 2021 |
| Bailey Home Interiors Limited | Professional & scientific | 2020 |
| Baileys Holdings Ltd | Real estate | 2018 |
| Bakertron INDUSTRIES101 Ltd | Financial services | 2026 |
| Balco Global Limited | Manufacturing | 2019 |
| Baldwin Associates Limited | Health & social care | 2011 |
| Balmer Designs Ltd | Hospitality | 2007 |
| Balnae Limited | Wholesale & retail | 2012 |
| BAM Consulting Services Limited | Professional & scientific | 2019 |
| BAM Groundworks Limited | Construction | 2025 |
| Bamboo Build Limited | Construction | 2016 |
| Bamford Management Services Limited | Professional & scientific | 2015 |
| Bamford Property Services Limited | Construction | 2015 |
| Bancey Developments Ltd | Real estate | 2024 |
| Banham Drive Ltd | Transport & logistics | 2013 |
| Baramundi Bars Limited | Hospitality | 2010 |
| Barball Limited | Manufacturing | 2024 |
| Barber Beauty Ltd | Other services | 2021 |
| Barber Studios Co. Ltd | Other services | 2026 |
| Barefoot Global Limited | Arts & recreation | 2019 |
| Barefoot Live Holdings Limited | Arts & recreation | 2019 |
| Barefoot Live Ltd | Arts & recreation | 2010 |
| Barefoot Sports App Ltd | Information & communication | 2026 |
| Barkers Electrical Limited | Construction | 2014 |
| Barley Park Management Company Limited | Households | 2023 |
| Barn Flats (Yatton Keynell) Limited(The) | Hospitality | 1976 |
| Barnes Plumbing & Heating Ltd | Construction | 2019 |
| Baroque Elite Horse Auctions LLP | | 2026 |
| Barrettsglobaltrading Ltd | Professional & scientific | 2024 |
| Barriers International Limited | Construction | 1994 |
| Barrow Farms Limited | Administrative & support | 2018 |
| Barry Holman Gardens Limited | Administrative & support | 2013 |
| BASE10 Design Limited | Manufacturing | 2021 |
| BASE10 Holdings Limited | Real estate | 2023 |
| Bath Basketball C.I.C. | Arts & recreation | 2023 |
| Bath Endocrinologist Ltd | Health & social care | 2022 |
| Bath Historical Buildings Trust | Construction | 1997 |
| Bath Outdoors Limited | Arts & recreation | 2021 |
| Bath Psychotherapy Limited | Health & social care | 2018 |
| Bath Self Storage Limited | Real estate | 2012 |
| Bath Style Limited | Construction | 1992 |
| Bath Water and Softeners Ltd | Wholesale & retail | 2024 |
| Bathwick Car and Van Hire Limited | Administrative & support | 2013 |
| Bathwood Limited | Professional & scientific | 2017 |
| Battersea and Wandsworth Chiropractors | Health & social care | 2007 |
| Bay Tree Barn 2 Ltd | Real estate | 2024 |
| Bay Tree Barn Ltd | Real estate | 2022 |
| Bayan Swim Ltd | Manufacturing | 2025 |
| Bayntum Limited | Financial services | 2024 |
| Bazbiff Ltd | Information & communication | 2025 |
| BB Precast Flooring Limited | Construction | 2012 |
| BC Company Holdings Ltd | Financial services | 2026 |
| BC Performance Media Ltd | Information & communication | 2026 |
| BCE Property Ltd | Real estate | 2019 |
| Bcpm Holdings Ltd | Wholesale & retail | 2025 |
| BDA Healthcare Ltd | Health & social care | 2019 |
| Bdbd Capital Ltd | Financial services | 2025 |
| BDP 720 Ltd | Real estate | 2021 |
| BE Happy Official Ltd | Professional & scientific | 2023 |
| Bear and Badger Limited | Construction | 2024 |
| Bear Worldwide Ltd | Wholesale & retail | 2022 |
| Beauchamp Marketing Limited | Professional & scientific | 1970 |
| Beaufort 12 Limited | Information & communication | 2012 |
| Beaufort Holdings Ltd | Professional & scientific | 2016 |
| Beaumont Clinic Ltd | Other services | 2025 |
| Beautinest Ltd | Wholesale & retail | 2025 |
| Beaux Arts (Bath) Limited | Wholesale & retail | 2015 |
| Beaux Arts Limited | Wholesale & retail | 1974 |
| Beckshights Company Limited | Health & social care | 2023 |
| Beech Communications Limited | Administrative & support | 2008 |
| Beechdean Farms Limited | Agriculture & fishing | 2013 |
| Beekind Pest Control Ltd | Administrative & support | 2022 |
| Beisorm Ltd | Agriculture & fishing | 2021 |
| Bellamys Design Limited | Information & communication | 2015 |
| Belle Aura Beauty Limited | Other services | 2022 |
| Belliniworks Limited | Professional & scientific | 2024 |