| Backtrack Systems Limited | Colchester | 2007 |
| Backvale Limited | Bridgend | 2026 |
| Backwell Limited | Bristol | 2000 |
| Backwell Logs Limited | Bristol | 2018 |
| Bacortem Ltd. | Edinburgh | 2003 |
| BAD BEE Ltd | Thornton Heath | 2025 |
| BAD Chunk Limited | Brierley Hill | 2006 |
| BAD Pictures Ltd | Margate | 2024 |
| Bada Bar Ltd | Twickenham | 2017 |
| Badeleks Ltd | West Bromwich | 2024 |
| Baden-Powell Ltd | London | 2022 |
| Badentoy Assets (NO 2) Limited | Manchester | 2012 |
| Badentoy Assets NO 1 Limited | Manchester | 2012 |
| Bader 1966 Limited | Birmingham | 2014 |
| Bader Geo-Consultancy Limited | Mansfield | 2011 |
| Badger Electrical Ltd | Bristol | 2021 |
| Badig Kiday Limited | Croydon | 2008 |
| Badin Invest Limited | London | 2008 |
| Badsey Fields Nurseries Limited | Evesham | 1972 |
| Baducreationz Ltd | Luton | 2021 |
| BAE Coffee Holdings Ltd | Wetherby | 2023 |
| BAE Systems (Nominees) Limited | Camberley | 1988 |
| BAE Systems (Projects) Limited | Camberley | 1947 |
| BAE Systems 2000 Pension Plan Trustees Limited | Camberley | 1998 |
| BAE Systems Deployed Systems Limited | Camberley | 1996 |
| BAE Systems Executive Pension Scheme Trustees Limited | Camberley | 1991 |
| BAE Systems Global Combat Systems Bridging Limited | Camberley, Surrey | 2002 |
| BAE Systems Land Systems ATF Limited | Camberley | 1999 |
| BAE Systems Land Systems Pinzgauer (Holdings) Limited | Camberley | 1999 |
| BAE Systems Marine (YSL) Limited | Camberley | 1966 |
| BAE Systems Pension Funds CIF Trustees Limited | Camberley | 1994 |
| BAE Systems Pension Funds Trustees Limited | Camberley | 1963 |
| BAE Systems Projects (Canada) Limited | Camberley | 1986 |
| BAE Systems Saudi Arabia (Vehicles and Equipment Holdings) Limited | Camberley | 2010 |
| BAE Systems Saudi Arabia (Vehicles and Equipment Nominees) Limited | Camberley | 2010 |
| BAG & Luggage Co AYR Limited | Kilmarnock | 2014 |
| BAG AGG Limited | Ipswich | 2014 |
| BAG Free Shopping Limited | Clay Hill | 2023 |
| BAG Free Shopping Taxi Limited | Clay Hill | 2023 |
| BAG Supplies Ltd | Crewe | 2000 |
| BAG Supply Company Europe Ltd | London | 2012 |
| Bagda Limited | Bury St. Edmunds | 2000 |
| Bageld Ltd | Portsmouth | 2020 |
| Bagforce Limited | Harby | 2015 |
| Bagga Bargain Limited | Southall | 2021 |
| Baggage Express (UK) Limited | Hayes | 1985 |
| Baggage Shipping Limited | Hayes | 2003 |
| Baggies Management Ltd | Warley | 2016 |
| Baggott & Baggott Ltd | Walsall | 2015 |
| Baghdad Medical Ltd | London | 2022 |
| Baghdad Wall International Trading Co., Ltd | Cambridge | 2020 |
| Baghera Limited | Folkestone | 2019 |
| Bagheri Ltd | London | 2012 |
| Bagift International Ltd. | London | 2013 |
| Baglan Cars Limited | Port Talbot | 2005 |
| Bagland Ltd | Beckenham | 2015 |
| Bagley Management Company Limited | Leominster | 2010 |
| Bagley Property Company Limited | Leominster | 2010 |
| Bagnall 2746 Locomotive Limited | Buxton | 2013 |
| Bagniamici Limited | York | 2011 |
| Bagno Trading Ltd | Cambridge | 2013 |
| Bags of Ideas Limited | Finchley | 2014 |
| Bags of Room Limited | Martock | 2023 |
| Bagshawe Estates (Wormhill) Limited | Nr Buxton | 1982 |
| Bagsy Ltd | Stoke-On-Trent | 2017 |
| Baguette Studios Ltd | Aldershot | 2024 |
| Baguley Bros.,Limited | Sutton Coldfield | 1935 |
| Bagus Muljadi Ltd | Nottingham | 2022 |
| BAH BAH Food Ltd | London | 2014 |
| Bahar 2016 Ltd | Hemel Hempstead | 2017 |
| Baharash Ltd | Enfield | 2021 |
| Bahdaf Ltd | Chippenham | 2023 |
| Bahia Flamingo Ltd | London | 2021 |
| Bahnstormer (Thames Valley) Limited | Alton | 2008 |
| Bahra Construction Ltd | Wolverhampton | 2025 |
| BAI JI 838 Limited | Glasgow | 2023 |
| BAI TE Import and Export Ltd | Beckenham | 2019 |
| Baia Ltd | London | 2025 |
| Baieluo Yuandong Interntional Group Ltd | Beckenham | 2020 |
| Baier Group (UK) Biology Engineering Ltd | Manchester | 2021 |
| Baiford Ltd | South Luffenham | 2024 |
| Baifu Limited | Oxford | 2014 |
| Baihe Marine Service Co., Ltd | Beckenham | 2021 |
| Bailanshi (UK) Ltd | Beckenham | 2020 |
| Baildon Properties Ltd | Huddersfield | 2006 |
| Baile Homes Limited | Skipton | 2017 |
| Baile Living Limited | Skipton | 2017 |
| Bailey Bears Ltd | Burton Upon Trent | 2021 |
| Bailey Building Management Ltd | Leeds | 2001 |
| Bailey C Limited | Redhill | 2012 |
| Bailey Digital Classroom Limited | Haverhill | 2022 |
| Bailey Distribution Services Ltd | Harlow | 2011 |
| Bailey Energy Limited | Leeds | 1993 |
| Bailey Group (UK) Ltd | Harlow | 2011 |
| Bailey Later Life Ltd | London | 2021 |
| Bailey Leasing Limited | Leeds | 2000 |
| Bailey Off-Site Limited | Leeds | 2005 |
| Bailey Oster Limited | Stockport | 2009 |
| Bailey Rail Limited | Leeds | 1999 |
| Bailey Roofing MK Ltd | Milton Keynes | 2020 |