| Blackwolf Creative Limited | Information & communication | 2019 |
| Bland Investments Ltd | Financial services | 2024 |
| Blaze Bidco Limited | Financial services | 2020 |
| Blended by Paige Limited | Other services | 2020 |
| Blended Hair (Rugby) Limited | Other services | 2025 |
| Blenz Coffee Ltd | Hospitality | 2025 |
| Blenz Ltd | Hospitality | 2021 |
| Blink Consulting Ltd | Professional & scientific | 2025 |
| Blkout Clothing Ltd | Wholesale & retail | 2018 |
| BLOCK79 Holdings Ltd | Real estate | 2025 |
| Blognami Ltd | Information & communication | 2024 |
| Bloom & Bloom Limited | Wholesale & retail | 2019 |
| Bloom Property Investments Ltd | Real estate | 2019 |
| BLU Building Consultants Limited | Professional & scientific | 2007 |
| Blue ARC Ltd | Wholesale & retail | 2020 |
| Blue Cedar Properties Limited | Real estate | 2022 |
| Blue Diamond Access Solutions Limited | Professional & scientific | 2002 |
| Blue Diamond Mechanical Ltd | Construction | 2019 |
| Blue Electricals Limited | Manufacturing | 2015 |
| Blue Lifestyle Ltd | Manufacturing | 2018 |
| Bluebell Wood (Lettings) Limited | Real estate | 2017 |
| Bluewater Boats Limited | Manufacturing | 2002 |
| Bluewood Ltd | Real estate | 2025 |
| Blythe Liggins LLP | | 2006 |
| Blythe Liggins Solicitors Limited | Professional & scientific | 1988 |
| BM Supply Co Ltd | Wholesale & retail | 2024 |
| Bmsc Global (UK) Limited | Wholesale & retail | 2020 |
| Boat Club Collective Limited | Administrative & support | 2018 |
| BOB Air Ltd | Manufacturing | 2024 |
| BOB Beck Fuel Injection Limited | Manufacturing | 2016 |
| Bobby's Properties Ltd | Real estate | 2020 |
| Body Balance With Yasmin Ltd | Health & social care | 2020 |
| Bolt Electrical Installations Limited | Construction | 2017 |
| BON Appetit Exotic Food Limited | Hospitality | 2026 |
| Bond Letting Limited | Real estate | 2021 |
| Bonnie and Grey Limited | Wholesale & retail | 2024 |
| Bookkeepers & Beyond Ltd | Professional & scientific | 2025 |
| Boom Radio DAB Ltd | Information & communication | 2020 |
| Boom Radio Ltd | Information & communication | 2020 |
| Borgies Baggies Limited | Professional & scientific | 2013 |
| Born Active Limited | Wholesale & retail | 2013 |
| Borrowing Ltd | Information & communication | 1996 |
| Bortonhall Limited | Manufacturing | 1980 |
| Boss Payment Watch Limited | Administrative & support | 2022 |
| BOT Property Limited | Real estate | 2024 |
| BOT Vehicle Consultants Limited | Professional & scientific | 2014 |
| Boughton Leigh Limited | Real estate | 2016 |
| Boula Ltd | Wholesale & retail | 2019 |
| Bould Strategy Limited | Professional & scientific | 2023 |
| Bouquet and Play Limited | Extraterritorial | 2021 |
| Bourne END Property (Industrial) Limited | Financial services | 2002 |
| BOW International Limited | Financial services | 2023 |
| Bowford Group Ltd | Construction | 2023 |
| Bowls England | Arts & recreation | 2007 |
| Box Haulage Ltd | Transport & logistics | 2018 |
| Boxmo Limited | Wholesale & retail | 2024 |
| Boxwave Limited | Professional & scientific | 2025 |
| Boxwave Movement CIC | Education | 2025 |
| BP Blue Limited | Hospitality | 2025 |
| BP Sounds International Limited | Professional & scientific | 2022 |
| Bp&T Consulting Limited | Professional & scientific | 2023 |
| BPS Warwick Limited | Professional & scientific | 2014 |
| Bracemead Consulting Limited | Professional & scientific | 2004 |
| Bracknell Land Limited | Real estate | 2009 |
| Bradard Limited | Wholesale & retail | 2024 |
| Braich Properties Limited | Real estate | 2018 |
| Braich Property Ltd | Real estate | 2026 |
| Brain Injury Case Management UK Limited | Professional & scientific | 2019 |
| Brakeley Ltd | Professional & scientific | 2010 |
| Brand Story Limited | Professional & scientific | 2019 |
| Brandon Place Management Company Limited | Households | 2023 |
| Brandwalk Ltd | Professional & scientific | 2015 |
| Brantech Solutions Ltd. | Information & communication | 2023 |
| Brear Associates Ltd | Professional & scientific | 2007 |
| Breathing Spaces Property Limited | Real estate | 2020 |
| Bredon View Glamping Limited | Hospitality | 2022 |
| Brellis Recruitment Limited | Administrative & support | 2018 |
| Brendan Petticrew Limited | Real estate | 2012 |
| Brennan Knight Ltd | Professional & scientific | 2004 |
| Brenron Ltd | Manufacturing | 2020 |
| Bressenden Associates Ltd | Professional & scientific | 2020 |
| Brewthyr Taverns Ltd | Hospitality | 2026 |
| Brian Coombes Limited | Administrative & support | 2014 |
| Brian Harding Environmental Ltd | Professional & scientific | 2021 |
| Brian Turner Building Services Ltd | Construction | 2021 |
| Briar Hill OUT of Hours Club Limited | Other services | 2016 |
| Brick Lane Group Limited | Extraterritorial | 2021 |
| Bricks and Mortar Assets Management Limited | Real estate | 2023 |
| Bricks and Mortar Capital Limited | Construction | 2019 |
| Bricks and Mortar Property Group Limited | Financial services | 2020 |
| Bricks and Mortar Property Investments Limited | Real estate | 2020 |
| Bricks N Pieces Ltd | Wholesale & retail | 2025 |
| Brickyard Agri Services Ltd | Professional & scientific | 2024 |
| Bridge Consulting Partnership Ltd | Information & communication | 2016 |
| Bridgefoot Holdings Limited | Financial services | 2018 |
| Bridget Rendell Limited | Information & communication | 2007 |
| Bright Bracket Ltd | Information & communication | 2015 |
| Bright Butterflies Property Investments Ltd | Households | 2019 |
| Bright Disposition Ltd | Administrative & support | 2015 |
| Bright Spine Publishing Ltd | Information & communication | 2026 |