| Blind Faith Tattoo Collective Ltd | Worthing | 2019 |
| Blind Lemon Ltd | London | 2025 |
| Blind River Ltd | Westerham | 2022 |
| Blind Samurai Films Limited | Tywyn | 2004 |
| Blind Summit Education | London | 2011 |
| Blind Swan Limited | Marlow | 2023 |
| Blind Tiger CIC | Stockton-On-Tees | 2023 |
| Blind Tiger Gaming Limited | Chorley | 2016 |
| Blind Tiger Tattoo Limited | North Shields | 2015 |
| Blinding Performance Limited | Shrewsbury | 2019 |
| Bling Glamour Models Ltd | Runcorn | 2024 |
| Blinko Productions Ltd | Swindon | 2024 |
| Blinq Group Ltd | London | 2025 |
| Blipaudio Ltd | Hove | 2014 |
| Blippi Entertainment Limited | London | 2019 |
| Bliss and Balance Movement Ltd | London | 2025 |
| Bliss Eventos Ltd | London | 2025 |
| Bliss Holiday Group Ltd | London | 2018 |
| Bliss Kids Academy Ltd | Nuneaton | 2019 |
| Bliss Music Limited | London | 2020 |
| Bliss Promotions Ltd | Yateley | 2023 |
| Bliss Publishing Ltd | London | 2021 |
| Bliss Yoga Studio Limited | Honiton | 2025 |
| Blissful Arches Ltd | Romford | 2026 |
| Blissfull Services (UK) Limited | Leicester | 2013 |
| Blissgsinging Ltd | Liverpool | 2025 |
| Blisworth FC Trading Limited | Northampton | 2021 |
| Blisworth Football Club Limited | Blisworth | 2021 |
| Blithfield Sailing Club Limited | Rugeley | 2023 |
| Blitz Competitions Limited | Nottingham | 2018 |
| Blitz Events Limited | Brighton | 2024 |
| Blitz Fit Ltd | London | 2025 |
| Blitz Hiit Limited | Street | 2023 |
| Blitz Yachting Ltd | London | 2024 |
| Blitzfitness Training Limited | London | 2021 |
| Blitzq Ltd | London | 2008 |
| Blitzy Productions Limited | Leigh On Sea | 2023 |
| BLK Box Fitness Group Limited | Newtownabbey | 2016 |
| BLK Fallow Limited | London | 2025 |
| BLK Kactus Limited | 5Th Floor | 2024 |
| Blkcurrent Ltd | London | 2022 |
| BLM Fest | London | 2021 |
| BLM Trade Ltd | Cambridge | 2014 |
| Blmp Limited | East Sussex | 1995 |
| Bloated Duck Limited | Southend On Sea | 2023 |
| Blobjam Ltd | London | 2025 |
| Bloc Climbing Ltd | Bristol | 2013 |
| Bloc Entertainment Ltd | Macclesfield | 2024 |
| Bloc International Limited | Walsall | 2023 |
| Bloc Projects Ltd | South Yorkshire | 2007 |
| Bloc Spaces Limited | Holt | 2012 |
| Bloc Studio Wellness Limited | Leeds | 2024 |
| Bloc Studios Limited | Sheffield | 2009 |
| Bloc Wellbeing CIC | Leeds | 2021 |
| Bloc. Padel Ltd | Beckenham | 2026 |
| BLOC10 Aberdeen Limited | Dundee | 2025 |
| Blocfit Ltd | Dartford | 2018 |
| Blochaus Climbing Ltd | Huddersfield | 2018 |
| Block Coaching Ltd | Bury St. Edmunds | 2026 |
| Block One Fitness Ltd | Saltney | 2022 |
| Block One Hub Ltd | Chester | 2026 |
| Block One Sports & Entertainment Ltd | Glasgow | 2023 |
| Block One Warrior Ltd | Chester | 2026 |
| Block Party Event Management Ltd | Eastbourne | 2022 |
| Block Records Ltd | Salisbury | 2023 |
| Block Universe CIC | London | 2015 |
| BLOCK10 Limited | Dundee | 2021 |
| BLOCK336 Limited | London | 2011 |
| BLOCK503 Limited | London | 2025 |
| Blockbuster the Musical Limited | London | 2012 |
| Blockception Ltd | Londonderry | 2017 |
| Blockheads Limited | Harlow | 2001 |
| Blockley Heritage Society | Moreton-In-Marsh | 2009 |
| Blockley Sports Club Utilities Limited | Blockley | 2003 |
| Blocksports International Limited | Cardiff | 2022 |
| Bloco Padel Ltd | Cardiff | 2026 |
| Blocturnal Ltd | London | 2023 |
| Blofeld Limited | Chigwell | 2018 |
| Blofield Tennis Club Limited | Great Yarmouth | 2014 |
| Blok London Limited | Clapton | 2015 |
| Blok Wolf Limited | London | 2019 |
| Blokland Ltd | Hook | 2020 |
| Blomonj Ltd. | Bristol | 2021 |
| Blomvyle Hall Shoot Ltd | Woodbridge | 2006 |
| Blonde Pilot Limited | Lancashire | 2001 |
| Blonde Sheep Events Limited | Herts | 2007 |
| Blondiez Ltd | Cheltenham | 2023 |
| Blondish Music Ltd | London | 2012 |
| Blonstein Events Limited | 91 Brick Lane | 2006 |
| Blood Line Tattoo Studio Ltd | Grays | 2012 |
| Blood Sweat & Muscle Ltd | Scunthorpe | 2017 |
| Blood Sweat & Tears Enterprises Ltd | Leeds | 2025 |
| Blood Sweat N Tears Ltd | Falkirk | 2017 |
| Blood, Sweat and Tea Productions Ltd | Walsall | 2020 |
| Bloodline Collective Ltd | Wisbech | 2026 |
| Bloodline Entertainment Limited | Washington | 2025 |
| Bloodline Inspire CIC | London | 2025 |
| Bloodline Israelite Studies and Research Centers (Bisarc) Ltd | Glasgow | 2024 |
| Bloodlines 2.0 Limited | London | 2024 |
| Bloodmoney Limited | London | 2023 |