| B&S Capital Trident (Holdings) Ltd | Northwood Hills | 2026 |
| B&S Cleaning Group Ltd | Nuneaton | 2025 |
| B&S Consulting Group Ltd | London | 2025 |
| B&S Exchange Ltd | Harrow | 2024 |
| B&S K (Angel 1) Ltd | Newcastle Upon Tyne | 2024 |
| B&T SPV Limited | London | 2021 |
| B&W Hold-In Ltd | London | 2023 |
| B&X Holdings Ltd | Acton | 2022 |
| B&Y Consultants Limited | London | 2000 |
| B-Advised Limited | Newcastle Upon Tyne | 2008 |
| B-Dacs Group Limited | Glasgow | 2021 |
| B-Engaged Holdings Limited | London | 2024 |
| B-Flexion Corporate Member (UK) Limited | London | 2011 |
| B-Group Holdings Limited | Redditch | 2024 |
| B-Hive Holdings Limited | Birmingham | 2022 |
| B-Jay's Services Limited | Lisburn | 2015 |
| B-Lafe Holdings Limited | Manchester | 2025 |
| B-Mac Mechanical Holding Ltd | Belfast | 2024 |
| B-P Asset Investments Ltd | Hounslow | 2026 |
| B-Recon Global Ltd | London | 2022 |
| B-Spoke Group Ltd | Bolton | 2020 |
| B-Tech AV Mounts Corporation Ltd | Daventry | 2022 |
| B-Ten Coote Limited | Reading | 2026 |
| B. & S. Investments (Manchester) Limited | London | 1995 |
| B. D. E. Holdings Limited | Askham | 2024 |
| B. Gallagher Trustee Limited | Leeds | 2023 |
| B. Hepworth and Company Holdings Limited | Redditch | 2025 |
| B. M. Jones Limited | London | 2013 |
| B. Mundell Holdings Limited | Tarbert | 2020 |
| B. Portwood & Company Limited | Bishop Auckland | 1963 |
| B. Roberts Equity Trading Ltd | Colchester | 2012 |
| B. Wellum Limited | | 1973 |
| B.46 Holdco Ltd | Poole | 2025 |
| B.46 Trustees Ltd. | Poole | 2014 |
| B.A. Media Holdings Limited | Birmingham | 2011 |
| B.A. Williams (Properties) Holdings Limited | Uxbridge | 2020 |
| B.A.G Services (Cheshunt) Limited | Hertford | 2013 |
| B.A.G. (N/E) Limited | Bishop Auckland | 2011 |
| B.A.M. Invest Ltd | Tadley | 2022 |
| B.A.S Capital Limited | Chelsea | 2020 |
| B.A.T. International Finance P.L.C. | London | 1972 |
| B.A.T. Operating Finance Limited | London | 2019 |
| B.A.T.A. Holdings Ltd | Sittingbourne | 2025 |
| B.A.T.S. Ilford Holdings Limited | London | 2025 |
| B.A.W. Coatings Holdings Ltd | Sheffield | 2020 |
| B.Aria Consults Limited | Basildon | 2017 |
| B.Arif Limited | Leicester | 2015 |
| B.B.Boak Holdings Limited | Cambridge | 2022 |
| B.B.D.A.&T. Ltd | Craigavon | 2026 |
| B.B.P.H. Limited | Barton Le Clay | 2010 |
| B.C.A. Group Ltd | Elland | 1981 |
| B.C.F. Travel Club Ltd | Horsham | 2011 |
| B.C.G Carat Group Company Ltd | London | 2020 |
| B.C.G Investments Limited | Benfleet | 2020 |
| B.C.S. Holdings (Scotland) Limited | Falkirk | 2017 |
| B.D.Cooke and Partners Limited | London | 1948 |
| B.D.W (Scotland) Ltd | Clydebank | 2022 |
| B.Dannatt Limited | Canvey Island | 1937 |
| B.E.S. Capital Holdings Limited | Bury St. Edmunds | 2024 |
| B.F.T. Holding Limited | London | 1998 |
| B.Fletcher Holdings Ltd | Nottingham | 2023 |
| B.Goulding Ltd | Chelmsford | 2025 |
| B.Grange Holdings Limited | Eastleigh | 2025 |
| B.Grn Group Ltd | London | 2021 |
| B.H. Picken Agricultural Services Limited | Heywood | 2022 |
| B.H.C.A. (Services) Limited | Kettering | 1991 |
| B.Hopper Advisory Ltd | Gloucester | 2022 |
| B.I. (UK) Limited | Oxfordshire | 1998 |
| B.I.B. (Darlington) Limited | London | 1981 |
| B.I.G Finance Limited | Willenhall | 2015 |
| B.I.L.L. (Holdings) Limited | Greenhithe | 2014 |
| B.J. Cadman Investments Limited | Colchester | 2025 |
| B.J. Cadman Properties Limited | Colchester | 2025 |
| B.J. Fennell Limited | York | 1972 |
| B.J.H Investment Management Limited | Mumbles | 2015 |
| B.K.G. Holdings Ltd | Buckingham | 2019 |
| B.K.L. Investments Limited | Manchester | 1968 |
| B.L.Nominees Limited | London | 1972 |
| B.L.S. Futures Limited | Bromley | 1993 |
| B.L.S. Insurance Services Limited | Altrincham | 2010 |
| B.Lloyd Holdings Ltd | Derby | 2023 |
| B.M Financials Limited | Great Dunmow | 2015 |
| B.M. Browne (UK Holdings) Limited | Tredegar | 1993 |
| B.M. Samuels Finance Group Ltd | Finchley | 1972 |
| B.M.Samuels Ltd | Finchley | 1965 |
| B.N Gibson Holdings Limited | Newark | 2017 |
| B.N.E.C Group Limited | Waterlooville | 2020 |
| B.P. Marsh Management Limited | London | 2014 |
| B.P.A.C. Holdings Limited | Portsmouth | 2015 |
| B.P.B. (Holdings) Limited | | 1990 |
| B.P.D. Solutions Ltd | Kilmarnock | 2011 |
| B.Prime Capital Limited | London | 2011 |
| B.R. Needham (Financial Services) Limited | Hertford | 1990 |
| B.R.A.I.N. Biotechnology Research and Information Network UK 2 Limited | Cardiff | 2018 |
| B.R.M. Consultancy Limited | Cambridge | 1993 |
| B.S. Birmingham Limited | Birmingham | 2014 |
| B.S. Fellows Holdings Limited | Haverhill | 2024 |
| B.S. Global Invest Limited | Hitchin | 2017 |
| B.S. Marson and Sons (Holdings) Limited | Newcastle Under Lyme | 1994 |
| B.S. Pension Fund Trustee Limited | Altrincham | 1920 |