| B9 Fuels Limited | Larne | 2021 |
| B9 International Limited | Dunstable | 2017 |
| B9T Management Ltd | Coventry | 2014 |
| B:Well Consulting Ltd | Bracknell | 2020 |
| BA & EL Whyte Limited | Cumnock | 2007 |
| BA Khem Arts Ltd | London | 2019 |
| BA Project Services Ltd | Huddersfield | 2015 |
| BA Safety & Security Solutions Limited | Huntingdon | 2024 |
| BA Sales & Lettings Ltd | London | 2013 |
| BA Surbiton Ltd | London | 2014 |
| BA1LEY Limited | Harrogate | 2020 |
| BA68 Ltd | Manchester | 2023 |
| Baamiis Limited | London | 2021 |
| Baaya Limited | London | 2025 |
| BAB Trade Co. Ltd | London | 2019 |
| Baba Atelier Limited | Bexhill On Sea | 2024 |
| Baba Construction (GB) Ltd | Southall | 2015 |
| Baba Jaga (Leeds) Limited | Leeds | 2016 |
| Baba JEE Poultry Limited | Solihull | 2009 |
| Baba Jerk Ltd | Aberystwyth | 2020 |
| Baba Works Limited | Sherborne | 2006 |
| Babas Snekkerservice Limited | London | 2023 |
| Babas Snekkerservice Sparebosse Limited | London | 2023 |
| Babator 6 Limited | London | 2023 |
| Babb Ltd | London | 2025 |
| Babbacombe 1967 Limited | Derby | 2013 |
| Babbage Way 1972 Limited | Sandhurst | 2014 |
| Babble (U.K.) Limited | Wallingford | 1996 |
| Babcock Corporate Secretaries Limited | London | 1995 |
| Babcock Engineering Limited | London | 2002 |
| Babcock Southern Careers Limited | London | 1995 |
| Babe Magnet Ltd | Harrogate | 2012 |
| Babes Brunch Ltd | Sevenoaks | 2024 |
| Babmaes Nominees Limited | Preston | 2005 |
| Baboas Group Limited | Beckenham | 2018 |
| Babolna BIO (UK) Limited | Melton Mowbray | 2002 |
| Babooco Limited | Sudbury | 1997 |
| Babush Ltd | London | 2024 |
| Baby Baby Limited | Harrow | 2005 |
| Baby Friend Maternal and Child Supplies Co., Ltd | Kington | 2025 |
| Baby Futur Mom&Baby Supplies Limited | London | 2017 |
| Baby M Ltd | Pinner | 2017 |
| Baby on Board.Uk Limited | Staines-Upon-Thames | 2015 |
| Baby Plus International Ltd | Cambridge | 2012 |
| Baby Store Sheffield Ltd | Sheffield | 2023 |
| Baby Swimming Company Limited | London | 2011 |
| Babylon Constructers Limited | Manchester | 2024 |
| Babysafe Norge Invest Limited | London | 2025 |
| Babysafe Norge Limited | London | 2025 |
| Babytrim Limited | Oxford | 2016 |
| Babyztore Ltd | 25 Hilltown Road | 2009 |
| BAC Attachments Limited | Haverhill | 2017 |
| BAC Green Holdings Ltd | London | 2019 |
| BAC Green Investments Limited | London | 2020 |
| Bacana Sangria UK Limited | Windsor | 2018 |
| Bacchus Developments Limited | Ingatestone | 2014 |
| Baccus Limited | Harrogate | 2026 |
| Bace Family Ltd | Spalding | 2020 |
| Bacement Limited | Arnold | 2014 |
| Bacess Engineering Ltd. | Hatfield | 2012 |
| Bachanal Limited | Kent | 2005 |
| Bachelors Avenue Property Management Ltd | Ballyclare | 2008 |
| Bachent Trading Ltd | Nottingham | 2022 |
| Bachy Limited | Burscough | 1997 |
| Back 2 Back Wellbeing Ltd | Stone | 2024 |
| Back 2 Wellness Ltd | Camberley | 2021 |
| Back BUT Wrong Ltd | Bristol | 2025 |
| Back Focus Limited | Stratford-Upon-Avon | 2025 |
| Back Gardens Cafe Ltd | Bristol | 2013 |
| Back in Shape Clinic Limited | Hereford | 2023 |
| Back in Shape Studio Limited | Hereford | 2023 |
| Back of the NET FC Limited | Northamptonshire | 2004 |
| Back to Africa Host Ltd | Winchester | 2019 |
| Back to Front Inside OUT Limited | Farnham | 2022 |
| Back to Nature Skincare Limited | Sutton-In-Ashfield | 2014 |
| Back to Origin Limited | Worcester | 2019 |
| Back to the Flat Films Ltd | London | 2007 |
| Back to the Past Limited | Reigate | 2009 |
| Back to Wood Limited | Godstone | 2021 |
| Back to Your Place Limited | Norwich | 2013 |
| Back, Gress and Vatisker Community Development Group Ltd | Stornoway | 2019 |
| Back-Ups Power Ltd | Huntingdon | 2022 |
| BACK2BACK Ltd | Bristol | 2007 |
| BACK2BUSINESS Limited | Bristol | 2007 |
| BACK2WORK Ltd. | Truro | 2016 |
| Backcote Limited | Bridgend | 2026 |
| Backdean Limited | London | 1998 |
| Backflow Ltd | London | 2025 |
| Backfold Limited | London | 2010 |
| Backfray Limited | Bridgend | 2026 |
| Backlane Limited | London | 1998 |
| Backlund Medical Services Invest Limited | London | 2020 |
| Backlund Medical Services Limited | London | 2020 |
| Backmoor Limited | Bridgend | 2025 |
| Backontrackcoffee Ltd. | London | 2013 |
| Backpass Productions Limited | Lichfield | 2025 |
| Backreed Limited | London | 1998 |
| Backrest Limited | Ravensden | 2009 |
| Backrise Limited | London | 1998 |
| Backstop Services Ltd | Leeds | 2009 |