| B Athletic Scotland Limited | Glasgow | 2026 |
| B B & B Leisure Parks Limited | Totnes | 2002 |
| B B B of C | Cardiff | 1997 |
| B B Falconry Experiences Limited | Risley | 2021 |
| B B Golf Limited | Thame | 2024 |
| B B Medicom Limited | Cardiff | 1987 |
| B Bounce Cardiff Limited | Cardiff | 2021 |
| B Collective Performing Arts Ltd | Elmstead, Colchester | 2025 |
| B Create Limited | Greenford | 2019 |
| B Delaney I R Limited | Otley | 2013 |
| B E Consultants Ltd | Leicester | 2026 |
| B F P M/Cr Ltd | Manchester | 2013 |
| B Festival Ltd | Longfield | 2011 |
| B G C (1991) Limited | Beaconsfield | 1991 |
| B J Sports Ltd | Chichester | 2013 |
| B K Bamber Bridge Limited | Lytham St. Annes | 2025 |
| B Leisure Limited | Basingstoke | 2025 |
| B Live Entertainment Limited | Shrewsbury | 2025 |
| B M Events & Shows Limited | Portsmouth | 2018 |
| B Magic Entertainment Ltd | Manchester | 2024 |
| B Martial Arts Ltd | Glasgow | 2026 |
| B Money Promotions Ltd | Bromsgrove | 2021 |
| B Movement LAB Ltd | Nottingham | 2024 |
| B Nuts Limited | Blackpool | 2018 |
| B P R C Event Management Limited | Isle Of Wight | 2001 |
| B Pilates Limited | London | 2017 |
| B R Elite Sports Ltd | Merseyside | 2015 |
| B RAY 28 Limited | Romney Marsh | 2019 |
| B Reyt Ltd | Shrewsbury | 2023 |
| B S C a Limited | Bromsgrove | 2010 |
| B Searle Rugby Ltd | Brierley Hill | 2023 |
| B Sharp Ltd | Lyme Regis | 2012 |
| B Strong Ltd | Mexborough | 2020 |
| B T a P S Limited | Driffield | 2021 |
| B Taylor & Sons Ltd | Hastings | 2013 |
| B Unique Management (UK) Limited | Holborn | 2011 |
| B Unique Records Limited | London | 2000 |
| B Visual ENT Ltd | Carshalton | 2019 |
| B W Motorsport Ltd | Belfast | 2007 |
| B W T Amusements Ltd | Bedford | 2017 |
| B Wood Projects Ltd | Northwich | 2025 |
| B Yoga Limited | Rugby | 2015 |
| B Z Team Ltd | Kenilworth | 2018 |
| B! Health and Fitness Ltd | Honiton | 2014 |
| B$B Limited | Sevenoaks | 2025 |
| B&B Fitness (C) Ltd | Ashford | 2024 |
| B&B Fitness Ltd | Ashford | 2023 |
| B&D Designs Limited | London | 1999 |
| B&E Co. Ltd | Ayr | 2024 |
| B&H Prestige Limited | Marlow | 2016 |
| B&J Locket Limited | Henley-On-Thames | 2023 |
| B&S Promotions Limited | Newport | 2024 |
| B&S-Fitness Limited | London | 2016 |
| B&T Sporting Events Ltd | Oswestry | 2018 |
| B&W Elite Juniors Kickboxing Ltd | Chippenham | 2024 |
| B&W Pursuits Ltd | Chichester | 2021 |
| B&W Road Racing Ltd | Craigavon | 2022 |
| B' Active 'N' B' Fit CIC | Sunderland | 2005 |
| B'S Fitness Training Ltd | Wolverhampton | 2026 |
| B-Active Health and Fitness Centre Limited | Birmingham | 2009 |
| B-Active Limited | Paisley | 2005 |
| B-Ali Empowered CIC | Sheffield | 2025 |
| B-All Sports Management Ltd | London | 2026 |
| B-Bub Productions Ltd | Congleton | 2016 |
| B-Dynamic Sports Ltd | London | 2026 |
| B-Features Limited | Richmond | 2022 |
| B-Fit Gyms Limited | Stockport | 2017 |
| B-Fit Halesworth Ltd | Halesworth | 2016 |
| B-Fit Health & Fitness Limited | Milford Haven | 2015 |
| B-Fit Lincs Ltd | Market Rasen | 2016 |
| B-Fit Studio Ltd | Stafford | 2017 |
| B-Fitt Fitness Ltd | Watford | 2013 |
| B-Hybrid Dance Ltd | London | 2019 |
| B-On Fitness Limited | Ballyclare | 2022 |
| B-Side Management Limited | London | 2020 |
| B-Side Multi Media Festival Community Interest Company | Portland | 2009 |
| B-Side Music Magazine Limited | Bury St. Edmunds | 2012 |
| B-Tac Productions Limited | London | 2025 |
| B-Twn International Limited | London | 2015 |
| B-Unique Catalogue 2 Limited | London | 2023 |
| B-Yoga Studio Ltd | Rhyl | 2024 |
| B. & N. Regal (Abingdon) Limited | Didcot | 1977 |
| B. & T. Parkin Limited | Canvey Island | 1965 |
| B. Dixon Music Services Ltd | Wigan | 2023 |
| B. G. Outsidaz F.C. Management & Development Limited | | 2003 |
| B. G. Racing Ltd | Aylesbury | 2007 |
| B. H. Sports Management Limited | Reddish | 2004 |
| B. Jamieson Golf Advisors Limited | Hook | 1995 |
| B. Marriott Design Ltd | Nottingham | 2025 |
| B. Misk Fitness Limited | Leicester | 2013 |
| B. R. T. Productions CIC | Brighton | 2014 |
| B. Smart Syndicates Limited | Thirsk | 2024 |
| B.A. Education London Ltd | Brighton | 2025 |
| B.A. Music Ltd | London | 2024 |
| B.A. Reclamation Limited | Mirfield | 1996 |
| B.A.D. Biscuit Productions Ltd | Brighton | 2023 |
| B.A.D. Songs Limited | London | 1985 |
| B.A.F. (Trading) Limited | Llangenwydd Road | 2002 |
| B.A.R.P. Limited | London | 2003 |
| B.C.M. Festivals Limited | Sittingbourne | 2001 |