| Butterflies Baby Ltd | Wholesale & retail | 2024 |
| Butterflies Counselling and Wellbeing Ltd | Health & social care | 2023 |
| Butterflies London Ltd | Wholesale & retail | 2026 |
| Butterfly & the BEE Ltd | Extraterritorial | 2025 |
| Butterfly and Blackberry Publishing Ltd | Extraterritorial | 2025 |
| Butterfly Bliss CIC | Education | 2024 |
| Butterfly Effect Beauty Ltd | Other services | 2024 |
| Butterfly Future Ltd | Information & communication | 2022 |
| Butterfly Kids Ltd | Health & social care | 2025 |
| Butterfox Holdings Ltd | Financial services | 2026 |
| Buttermilk Events Ltd | Hospitality | 2024 |
| Butterstile Investments Ltd | Real estate | 2016 |
| Butterstile Cleaning Ltd | Other services | 2021 |
| Butterstile Properties Limited | Real estate | 2003 |
| Butterstyle Convenience Store Limited | Wholesale & retail | 2015 |
| Butterworth Developers Limited | Professional & scientific | 2009 |
| Butterworth Gardens (Chorley) Residents Association Limited | Households | 2003 |
| Butterworths Developers Limited | Professional & scientific | 2001 |
| Butterworths Lettings Limited | Real estate | 2006 |
| Butties R US Limited | Hospitality | 2016 |
| Button Burgers Ltd | Hospitality | 2025 |
| Button Monkey Editing Ltd | Information & communication | 2015 |
| Button Monkey TV Ltd | Information & communication | 2009 |
| Buttons & Bows Ltd | Extraterritorial | 2003 |
| Buttress Architects Ltd | Professional & scientific | 2005 |
| Buttress Badge C.I.C. | Professional & scientific | 2014 |
| Buttress EOT Limited | Extraterritorial | 2025 |
| Butty Style Ltd | Hospitality | 2022 |
| Buuk and PIN Ltd | Wholesale & retail | 2024 |
| Buump Limited | Information & communication | 2016 |
| Buvette Ambition Consultant Limited | Other services | 2026 |
| Buwe Ltd. | Health & social care | 2015 |
| BUX Locum Ltd | Health & social care | 2024 |
| Buxton Finch Ltd | Real estate | 2019 |
| Buxton Peak Limited | Real estate | 2022 |
| Buy and Hold Limited | Hospitality | 2023 |
| Buy Depot Ltd | Real estate | 2021 |
| Buy Design Ltd | Construction | 2013 |
| Buy Happiness Ltd | Wholesale & retail | 2024 |
| Buy IT From the Internet Ltd | Wholesale & retail | 2021 |
| Buy ME Media Ltd | Professional & scientific | 2016 |
| Buy My Car Manchester Limited | Administrative & support | 2026 |
| Buy PAY International Ltd | Other services | 2026 |
| Buy Shop Trade Ltd | Wholesale & retail | 2025 |
| Buy Trendz Ltd | Wholesale & retail | 2025 |
| Buy, Sell, Exchange (Manchester) Ltd | Wholesale & retail | 2016 |
| BUY2HELP Limited | Wholesale & retail | 2023 |
| BUY2USE Ltd | Wholesale & retail | 2026 |
| Buydeals Limited | Wholesale & retail | 2024 |
| Buydiscounts Ltd | Wholesale & retail | 2025 |
| Buyer Solution Ltd | Wholesale & retail | 2022 |
| Buyers Bay Ltd | Wholesale & retail | 2024 |
| Buyersempire Limited | Wholesale & retail | 2016 |
| Buyerzhome Limited | Wholesale & retail | 2015 |
| Buyex Support Ltd | Wholesale & retail | 2025 |
| Buyforge Limited | Wholesale & retail | 2025 |
| Buygenix Ltd | Wholesale & retail | 2025 |
| Buyhere Ltd | Wholesale & retail | 2022 |
| BUYHIV3 Ltd | Wholesale & retail | 2025 |
| BUYIN2IT.CO.UK Limited | Extraterritorial | 2011 |
| Buying Point Ltd | Wholesale & retail | 2025 |
| Buyit Construction Ltd | Construction | 2023 |
| Buyit Finance Ltd | Financial services | 2023 |
| Buyme Direct Ltd | Wholesale & retail | 2024 |
| Buymedia Limited | Information & communication | 2025 |
| Buynew Ltd | Wholesale & retail | 2025 |
| Buyolian Ltd | Wholesale & retail | 2025 |
| Buyond Limited | Wholesale & retail | 2025 |
| Buyondo Services Ltd | Health & social care | 2019 |
| Buyrite Limited | Wholesale & retail | 2025 |
| Buysell Cars Ltd | Wholesale & retail | 2026 |
| Buystrix Ltd | Wholesale & retail | 2025 |
| Buyswapsell Limited | Wholesale & retail | 2000 |
| Buytogive Ltd | Administrative & support | 2025 |
| Buyvo Limited | Wholesale & retail | 2026 |
| Buywise Trading Ltd | Wholesale & retail | 2026 |
| Buyzauk Ltd | Wholesale & retail | 2025 |
| Buzz Business Limited | Financial services | 2024 |
| Buzz in Cleaning Ltd | Manufacturing | 2026 |
| Buzz Industries Limited | Administrative & support | 2024 |
| Buzz Interior Limited | Professional & scientific | 2023 |
| Buzz Payroll Solutions Limited | Administrative & support | 2021 |
| Buzz Utilities Limited | Professional & scientific | 2019 |
| Buzz Ventures Ltd | Real estate | 2016 |
| Buzzbear Design & Marketing Ltd | Professional & scientific | 2024 |
| Buzzd Ltd | Information & communication | 2025 |
| Buzzflow Ltd | Wholesale & retail | 2025 |
| Buzzin' Meeples Ltd | Wholesale & retail | 2021 |
| Buzzrocks Caribbean Caterers Limited | Hospitality | 2005 |
| Buzzworthy Events Limited | Hospitality | 2026 |
| BVA Group Limited | Financial services | 2023 |
| Bvje Consultancy Services Ltd | Professional & scientific | 2025 |
| BVK Advisory Ltd | Professional & scientific | 2017 |
| BVK Social Care Limited | Health & social care | 2022 |
| BVR Developments Ltd | Real estate | 2024 |
| Bvsca Care Limited | Health & social care | 2025 |
| BW Cosmetics Consultants Ltd | Professional & scientific | 2025 |
| BW Emea Holdings Limited | Professional & scientific | 2022 |
| BW Management Services Limited | Real estate | 2020 |
| BW Pick and MIX Company Limited | Wholesale & retail | 2019 |