| B N Construction UK Limited | Polegate | 2009 |
| B Natural Limited | Hitchin | 2011 |
| B Never TOO Busy to BE Beautiful Limited | Dorset | 2003 |
| B of E Finance Limited | Edinburgh | 1989 |
| B of E Properties Limited | Edinburgh | 1990 |
| B P Lloyd Asset Management Ltd | Rhyl | 2019 |
| B P M a Limited | Ipswich | 2009 |
| B P Rail Services Limited | Bristol | 2013 |
| B Rhodes & Sons Limited | Stockport | 2020 |
| B S Bikes Limited | Stoke On Trent | 2011 |
| B S C C Investments Limited | Witney | 2015 |
| B S G Projects Limited | Tonbridge | 1998 |
| B Shares EOT Ltd | London | 2022 |
| B Stream Ltd | London | 2022 |
| B the B Limited | Merthyr Tydfil | 2012 |
| B Thomson Building Contractors Ltd. | Orkney | 2012 |
| B V I Limited | Malvern | 2006 |
| B V Leasing Ltd | Wakefield | 2015 |
| B W Belding Limited | Spalding | 2023 |
| B W Distribution Ltd | Saffron Walden | 2018 |
| B Wellness Ltd | Leeds | 2019 |
| B&C Advanced Ceramics Co., Ltd | London | 2014 |
| B&C Floridita SA / Ltd | London | 2019 |
| B&Ce Holdings Limited | Crawley | 2021 |
| B&D Secretarial Services Limited | Gainsborough | 2003 |
| B&Es Building & Engineering Services Association Limited | Penrith | 2011 |
| B&G International (FAR East) Limited | Beckenham | 2011 |
| B&G Management Ltd | Edinburgh | 2012 |
| B&H Leach Limited | Aberdare | 2024 |
| B&H Trading Limited | Houghton Le Spring | 2022 |
| B&I Global Trading Co., Ltd | Beckenham | 2023 |
| B&J Facade Ltd | London | 2017 |
| B&M Consulting Ltd | London | 2018 |
| B&R Precision Bearing Limited | London | 2022 |
| B&S Midlands Link Ltd | Birmingham | 2021 |
| B&Y Asset Holdings Ltd | London | 2024 |
| B-Fab Logistics Limited | Newhaven | 2020 |
| B-Hive Property Solutions Limited | Richmond | 2017 |
| B-Lands Consulting Ltd | Rugby | 2019 |
| B-Loony (U.K.) Limited | Chesham | 1984 |
| B-Loony Trustee Limited | Chesham | 2023 |
| B. & E. Boys (Developments) Limited | Rossendale | 1984 |
| B. & E. Boys (Properties) Limited | Rossendale | 1986 |
| B. Bernard & Sons Limited | Sutton Coldfield | 1983 |
| B. Entwistle (Bacon) Limited | Manchester | 2004 |
| B. Price Holdings Limited | Birmingham | 2009 |
| B. Smart Racing Limited | Thirsk | 2024 |
| B.& R.Sigmar Limited | London | 1946 |
| B.A. (NO.1) Limited | Exeter | 1991 |
| B.A.C.D. RTM Company Limited | London | 2012 |
| B.A.N.Y.-G Ltd | Haverfordwest | 2024 |
| B.A.T. Motor Sports Limited | | 2003 |
| B.C.S. Disposables Limited | Lancashire | 2001 |
| B.C.S. Systems Limited | Ilminster | 1987 |
| B.E.T. Building Services Limited | Crawley | 1984 |
| B.Fordyce Limited | London | 1948 |
| B.G. Consort Limited | London | 1948 |
| B.I. Groundwork Construction Limited | Oakham | 1997 |
| B.I.E. Collegia ET Academiae Limited | London | 2007 |
| B.I.G Brand Impact GRP Limited | Reading | 2014 |
| B.J. MIN Limited | Woodbury Salterton | 1997 |
| B.K. Limited | Whyteleafe | 2016 |
| B.L.K Brickwork Ltd | Birmingham | 2017 |
| B.M.C. Climbing Walls Limited | Manchester | 1988 |
| B.M.C. Fruit & Produce Ltd. | Belfast | 1985 |
| B.O.C Manufacturing Limited | Blyth | 2021 |
| B.O.M Crane Services Ltd | Coventry | 2024 |
| B.P. Sanders and Company Limited | Watford | 2022 |
| B.Payne & SON Limited | Manchester | 1962 |
| B.R.S.A. Services Company Limited | Alvechurch | 1988 |
| B.S.A. Motor Cycles Limited | Chandlers Ford | 2011 |
| B.S.Glass Co., Ltd | Beckenham | 2016 |
| B.T.F.P. Limited | Chippenham | 2010 |
| B1 Enterprises Ltd | Wolverhampton | 2011 |
| B1 GAS Limited | Chesterfield | 2012 |
| B100 Limited | Seaford | 2006 |
| B17 Preservation Limited | Surbiton | 1983 |
| B1CEP Ltd | Harrogate | 2016 |
| B1LL Ltd | Harrogate | 2026 |
| B1NANCE Limited | Harrogate | 2021 |
| B1O Ltd | Harrogate | 2026 |
| B1TCOIN Ltd | Harrogate | 2021 |
| B2 (Eckington) Limited | Malvern | 2015 |
| B2B Energy Solutions Ltd. | Canvey Island | 2010 |
| B2B Research Limited | Somerset | 2007 |
| B2B Research Surveys Limited | London | 2017 |
| B2B Sweden Limited | London | 2014 |
| B2B Tools Ltd | London | 2017 |
| B2E Resourcing Limited | London | 2017 |
| B2R Capital Limited | Southend-On-Sea | 2014 |
| B2R Finance Limited | Southend-On-Sea | 2014 |
| B2R Limited | Sandhurst | 2022 |
| B3 Homes (Esher) Ltd | Chippenham | 2020 |
| B3S NO.2 Limited | London | 2004 |
| B4RRY Limited | Harrogate | 2021 |
| B63 Ltd | Halesowen | 2019 |
| B7 Investments II Limited | Manchester | 2015 |
| B7 Media Limited | Maidenhead | 2008 |
| B80 Arrow Mews Owners Management Limited | Studley | 2016 |
| B9 Biogas Ltd | Larne | 2011 |