| Blessed Fellowship Limited | Other services | 2023 |
| Blessed IT Ltd | Other services | 2020 |
| Blessed Men's Barber Ltd | Other services | 2019 |
| Blest Times Ltd | Health & social care | 2016 |
| Bleu Beauty and Wellness Ltd | Other services | 2017 |
| Blingstyle Ltd | Wholesale & retail | 2024 |
| Blinko Productions Ltd | Arts & recreation | 2024 |
| Bliss Beauty Limited | Other services | 2014 |
| Bliss Cleaning & Maintenance Ltd | Administrative & support | 2018 |
| Blizzard Blue Accountancy Limited | Professional & scientific | 2013 |
| BLM Accountancy Ltd | Professional & scientific | 2012 |
| Block 3 Studio Ltd | Wholesale & retail | 2024 |
| Block Management Ltd | Real estate | 2017 |
| Blockhaus Ltd | Financial services | 2025 |
| Bloom and Blossom Limited | Manufacturing | 2008 |
| Bloomin Beautiful Limited | Other services | 2013 |
| Bloomsoft Solutions Limited | Information & communication | 2016 |
| Blossom Barn Limited | Wholesale & retail | 2011 |
| Blossom Housekeeping Ltd | Administrative & support | 2025 |
| Blount & Maslin Limited | Real estate | 2001 |
| Blrr Limited | Health & social care | 2023 |
| Blubook Limited | Professional & scientific | 2017 |
| Blue Brigade Club Limited | Arts & recreation | 2023 |
| Blue Danube Property Ltd | Real estate | 2026 |
| Blue Elephant Accountants Limited | Professional & scientific | 2024 |
| Blue EMU Malmesbury Ltd | Hospitality | 2023 |
| Blue Event Investments Limited | Real estate | 2023 |
| Blue Events Enterprise Limited | Information & communication | 2018 |
| Blue Eyes Cleaning Services Ltd | Administrative & support | 2018 |
| Blue Glass Films Limited | Information & communication | 2024 |
| Blue Line Sports Limited | Wholesale & retail | 2010 |
| Blue Mountain Equp TRD UK Ltd | Wholesale & retail | 2021 |
| Blue Ridge Projects Limited | Arts & recreation | 2014 |
| Blue Sky PM Ltd | Professional & scientific | 2016 |
| Blue T Marketing Limited | Professional & scientific | 2023 |
| Blue Tesseract Ltd | Professional & scientific | 2023 |
| Blue Tongue 117 Limited | Real estate | 2018 |
| Blue Tongue Construction Limited | Construction | 2017 |
| Blue Tongue Limited | Construction | 2012 |
| Blue WEX International Ltd | Administrative & support | 2023 |
| Bluebells Swindon Management Company (NO 2) Limited | Households | 2007 |
| Bluebells Swindon Management Company (NO 3) Limited | Households | 2007 |
| Bluegum Solutions Limited | Real estate | 2014 |
| Bluehouse Fmcg Limited | Professional & scientific | 2025 |
| Bluemask Solutions (UK) Limited | Information & communication | 2024 |
| Blues Cafe Bar Limited | Hospitality | 2002 |
| Blues Developments Limited | Construction | 2024 |
| Blues Properties Ltd | Real estate | 2024 |
| Bluestone City Limited | Manufacturing | 1996 |
| Bluestones Trading Ltd | Professional & scientific | 2017 |
| Bluewood Properties Ltd | Real estate | 2014 |
| Blunsdon Abbey Holdings Limited | Administrative & support | 2022 |
| Blunsdon Abbey Limited | Administrative & support | 2016 |
| Blunsdon Blinds Ltd | Wholesale & retail | 2021 |
| Blunsdon Pre-School Limited | Education | 2016 |
| Blush Nails and Beauty Ltd | Other services | 2024 |
| BLW Trading Ltd | Wholesale & retail | 2026 |
| BM Edwards Limited | Financial services | 2025 |
| BM Property and Construction Services Limited | Construction | 2025 |
| BMG Customs Ltd | Administrative & support | 2016 |
| BMK Liquid Roofing Systems Ltd | Construction | 2025 |
| BNG Services Limited | Professional & scientific | 2008 |
| BNL Accounting Services Ltd | Professional & scientific | 2017 |
| BNP Paribas Fleet Holdings Limited | Financial services | 2000 |
| BNP Properties Ltd | Real estate | 2021 |
| Boasiako Limited | Transport & logistics | 2025 |
| BOB a Carter Limited | Extraterritorial | 2019 |
| BOB for the JOB Limited | Administrative & support | 2025 |
| BOB Kelly Project Management Limited | Professional & scientific | 2011 |
| BOB Posner Limited | Professional & scientific | 2014 |
| BOB Special Transporting Ltd | Transport & logistics | 2019 |
| BOB Trans Ltd | Transport & logistics | 2019 |
| BOB Wiseman Limited | Wholesale & retail | 2002 |
| Bobade Ltd | Professional & scientific | 2026 |
| Bobjacks Construction Ltd | Construction | 2023 |
| Bobok Ltd | Wholesale & retail | 2026 |
| Bobozam Limited | Public administration | 2024 |
| Bobsy's Ltd | Construction | 2024 |
| Bockhampton Developments Limited | Construction | 2014 |
| Bodhi Watch Limited | Information & communication | 2018 |
| Body Beauty by Bernice Limited | Other services | 2000 |
| BOE Furniture Ltd | Manufacturing | 2020 |
| Bogrol Ltd | Manufacturing | 2026 |
| Bolingbroke Arms & Hotel Limited | Hospitality | 2008 |
| Bolingbroke Capital Management Ltd | Professional & scientific | 2019 |
| Bolingbroke Capital Partners LLP | | 2025 |
| Bolingbroke Group Ltd | Financial services | 2026 |
| Bolingbroke Partners Nominee Ltd | Professional & scientific | 2025 |
| Bolingbroke Patterson Ltd | Financial services | 2021 |
| Bolsover Urban Development Trust Company Limited | Professional & scientific | 1987 |
| Bombay Curry House Swindon Ltd | Hospitality | 2025 |
| Bombers Sports Bar Limited | Hospitality | 2023 |
| Bond Global Solutions Ltd | Professional & scientific | 2020 |
| Bonded Consulting Ltd | Information & communication | 2025 |
| Bonello Carpentry Limited | Construction | 2014 |
| Bonnetti Consulting Limited | Professional & scientific | 2015 |
| Bonneywell Development Ltd. | Professional & scientific | 2017 |
| Books & Stationers Limited | Wholesale & retail | 2011 |
| Booktrees Limited | Information & communication | 2024 |
| Boom Lifts Investments Ltd | Real estate | 2025 |