| Blitz Kitchen Ltd | Hospitality | 2026 |
| BLJ Property Limited | Real estate | 2019 |
| BLK Investment Properties Ltd | Construction | 2018 |
| Block One Hub Ltd | Arts & recreation | 2026 |
| Block One Warrior Ltd | Arts & recreation | 2026 |
| Blocklavish Limited | Wholesale & retail | 1986 |
| Blocvue Limited | Information & communication | 2026 |
| Blog Writing Services UK Ltd | Information & communication | 2020 |
| Blood Moon Films Ltd | Information & communication | 2025 |
| Bloom Collaborative CIC | Education | 2023 |
| Bloom Hearing Specialists Limited | Real estate | 2004 |
| Bloom Planet Ltd | Administrative & support | 2022 |
| Blooplight VFX Limited | Information & communication | 2010 |
| Blox (UK) Ltd | Extraterritorial | 2014 |
| Blpr Ltd | Households | 2023 |
| BLT Cheshire Limited | Professional & scientific | 2013 |
| BLU Cloud Limited | Real estate | 2024 |
| Blue and White UK Holdings | Financial services | 2020 |
| Blue Bell (Buckley) Limited | Wholesale & retail | 2006 |
| Blue Bell 1494 Ltd | Hospitality | 2015 |
| Blue Block Properties Ltd | Real estate | 2017 |
| Blue Centurion Limited | Administrative & support | 2018 |
| Blue Chilli T/A Indian.Com Ltd | Hospitality | 2022 |
| Blue Chip Technology Limited | Manufacturing | 1995 |
| Blue Chip Technology Trustees Limited | Professional & scientific | 2017 |
| Blue Column Properties Limited | Real estate | 2019 |
| Blue Diamond Industrial Supplies Limited | Wholesale & retail | 2013 |
| Blue JAY Theatre Company Ltd | Arts & recreation | 2025 |
| Blue Lagoon Kebab Ltd | Hospitality | 2024 |
| Blue OWL Consultants Ltd | Professional & scientific | 2025 |
| Blue PEA POD Limited | Professional & scientific | 2005 |
| Blue Planet Products Limited | Administrative & support | 2018 |
| Blue Ribbon Community Care Ltd | Health & social care | 2009 |
| Blue Sky Facilities UK Ltd | Administrative & support | 2006 |
| Blue Spire Cargo Ltd | Transport & logistics | 2025 |
| Blue STD Ltd | Real estate | 2023 |
| Blue Touch Paper Records Ltd | Information & communication | 2011 |
| Blue Water Telecoms Limited | Wholesale & retail | 2017 |
| Blue Wigwam Biodiversity Limited | Administrative & support | 2023 |
| Blue Wigwam Holdings Limited | Administrative & support | 2024 |
| Blue Wigwam Limited | Construction | 2014 |
| BLUE2GLOBAL Limited | Information & communication | 2019 |
| Bluealex Ltd | Health & social care | 2017 |
| Bluebelle Professional Services Limited | Professional & scientific | 2023 |
| Bluedoor Property Management Ltd | Real estate | 2022 |
| Bluemarble Investment Limited | Real estate | 2019 |
| Blueoak Estates (Altrincham) Limited | Construction | 2024 |
| Blueoak Estates (Aspect House) Limited | Construction | 2026 |
| Blueoak Estates (Centurion) Limited | Real estate | 2022 |
| Blueoak Estates (Cheshire) Limited | Construction | 2014 |
| Blueoak Estates (Chester) Limited | Construction | 2014 |
| Blueoak Estates (Christleton) Limited | Construction | 2015 |
| Blueoak Estates (Construction) Ltd | Construction | 2014 |
| Blueoak Estates (DE Bunsen Hall) Limited | Construction | 2026 |
| Blueoak Estates (Deva) Limited | Real estate | 2016 |
| Blueoak Estates (Investments) Limited | Real estate | 2018 |
| Blueoak Estates (Manchester) Limited | Construction | 2021 |
| Blueoak Estates (Meols Drive) Limited | Construction | 2023 |
| Blueoak Estates (Sale Point) Limited | Construction | 2024 |
| Blueoak Estates (ST Luke's) Limited | Construction | 2017 |
| Blueoak Estates (Station House) Ltd | Construction | 2017 |
| Blueoak Estates (West Kirby) Limited | Construction | 2014 |
| Blueoak Estates (Westminster) Ltd | Construction | 2017 |
| Blueoak Estates (Wirral) Limited | Construction | 2022 |
| Blueoak Estates Hoylake Limited | Construction | 2020 |
| Blueoak Estates Limited | Construction | 2003 |
| Blueprint Living Limited | Real estate | 2026 |
| Blueseed Technology Limited | Professional & scientific | 2012 |
| Bluestone Bar Ltd | Hospitality | 2020 |
| Bluestones 360 Limited | Administrative & support | 2015 |
| Bluestones Equity Partners Limited | Financial services | 2022 |
| Bluestones Growth Share Scheme Limited | Professional & scientific | 2024 |
| Bluestones Investment Group - Professional Services Limited | Administrative & support | 2016 |
| Bluestones Investment Group - Specialist Services Limited | Administrative & support | 2016 |
| Bluestones Investment Group Limited | Administrative & support | 2011 |
| Bluestones Logistics Limited | Administrative & support | 2014 |
| Bluestones Medical Complex Care Limited | Administrative & support | 2018 |
| Bluestones Medical Recruitment Limited | Administrative & support | 2011 |
| Bluestones Offshore Solutions Partner Limited | Administrative & support | 2014 |
| Bluestones One Installations Limited | Administrative & support | 2015 |
| Bluestones One Merchandising Limited | Other services | 2017 |
| Bluestones One Store Development Limited | Administrative & support | 2018 |
| Bluestones Staffing N.I. Limited | Construction | 2018 |
| Bluestones Supply Chain (North West) Limited | Administrative & support | 2014 |
| Bluestones Supply Chain Limited | Administrative & support | 2014 |
| Bluetooth Systems Ltd | Professional & scientific | 2022 |
| Bluetop Solar Parking UK Limited | Transport & logistics | 2022 |
| Blusky Brands Ltd | Wholesale & retail | 2021 |
| BM Limitless Solutions UK Ltd | Wholesale & retail | 2021 |
| BMD (NW) Ltd | Construction | 2022 |
| BMS Saltney Ltd | Wholesale & retail | 2026 |
| BN International Commodity Brokers Ltd | Wholesale & retail | 2017 |
| BO Transport Services Ltd | Transport & logistics | 2014 |
| Boarstatant Limited | Agriculture & fishing | 2014 |
| BOB Best (Liverpool) Limited | Wholesale & retail | 1979 |
| BOB Hill Associates Limited | Professional & scientific | 2015 |
| BOB Parry and Company Limited | Real estate | 1927 |
| Bob's Motorcycle and Tyres Ltd | Manufacturing | 2018 |
| Bodecker Limited | Professional & scientific | 2008 |
| Bodhi Yoga and Wellness Ltd | Arts & recreation | 2018 |