| Bailey Systems Limited | Leeds | 2000 |
| Bailey Truck Solutions Limited | Peterborough | 2023 |
| Bailey Tutoring Ltd | Bolton | 2021 |
| Bailey's Emporium Ltd | Doncaster | 2020 |
| Bailey,Wilson & Company Limited | Clayton | 1920 |
| Baileys Contracting Ltd | Macclesfield | 2022 |
| Baileys Law Legal Services Ltd | Bodmin | 2015 |
| Baileys Skiphire ( Corby) Ltd | Corby | 2013 |
| Bailies Development Management Company Limited | Newtownards | 2002 |
| Baillies Mills Accordion Band Ltd | Lisburn | 2011 |
| Bailprint SA Limited | Chorley | 2008 |
| Bailwood Trustee Limited | Hull | 2024 |
| Baily Court Management Company Limited | Bristol | 2024 |
| Bain and Gray Trustee Limited | London | 2023 |
| Bain Solutions UK Limited | Hove | 2023 |
| Bainbridge Corporation Ltd | Luton | 2014 |
| Bainergy Ltd. | Fraserburgh | 2009 |
| Bains Coaches Limited | Inverurie | 1988 |
| Bains Sisters Limited | Rugby | 2017 |
| Bainthorne Advisory Ltd | Eastleigh | 2025 |
| Baird Metals Limited | Beckenham | 2015 |
| Baird Street Developments Limited | Manchester | 2013 |
| Bairstow Ltd | Halifax | 2024 |
| Bairstow Street Freehold Co Limited | Lytham St Annes | 2014 |
| Baishun Hardware Co., Ltd | Beckenham | 2017 |
| Bait Bank Ltd | Kirkby Stephen | 2012 |
| Baitsons Limited | Hull | 2012 |
| Baixiang Trading Co., Limited | London | 2021 |
| Baiyi International Inc Limited | London | 2006 |
| Baiyun International Trading Co., Ltd | Cambridge | 2010 |
| BAJ Coatings Limited | Hemel Hempstead | 1958 |
| BAJ Property Developments Limited | London | 2015 |
| Bajoo & Co Ltd | Huntingdon | 2020 |
| BAK2BASIKS Ltd | Coalville | 2010 |
| Bakchich ST Johns Ltd | Liverpool | 2016 |
| Bake Design Ltd | Barry | 2022 |
| Bake ME UP Ltd | Harrow | 2022 |
| Bake O Clock Ltd | London | 2019 |
| Baked & Frosted Ltd | Edinburgh | 2023 |
| Baked North Limited | Carlisle | 2020 |
| Bakemail Limited | Stratford-Upon-Avon | 2015 |
| Baker and Barker Ltd | Carlisle | 2014 |
| Baker Consulting Ltd | Bristol | 2018 |
| Baker Family Ltd | London | 2016 |
| Baker Group Ltd | Bristol | 2003 |
| Baker Hughes (BJ) Ltd. | Aberdeen | 1985 |
| Baker Noel Bookkeeping & Payroll Limited | Bedford | 2021 |
| Baker Noel Bookkeeping Limited | Bedford | 2021 |
| Baker Noel Payroll Limited | Bedford | 2021 |
| Baker Petrolite Limited | London | 1955 |
| Baker Reign Limited | Leicester | 2014 |
| Baker Richards Employee Trustee Limited | Cambridge | 2020 |
| Baker UK Holdings Ltd | Eastbourne | 2018 |
| Bakers (Area 1) Limited | Preston | 1961 |
| Bakers Broker Limited | Darwen | 2023 |
| Bakery Court Management Limited | Oxford | 2013 |
| Bakery Mews RTE Company Limited | Hemel Hempstead | 2009 |
| Bakkafrost UK Limited | Nottingham | 1995 |
| Bakkar Limited | Doncaster | 2014 |
| Bakkavor Acquisitions (2008) Limited | London | 2008 |
| Bakkavor Brothers Limited | London | 1972 |
| Bakkavor Dormant Holdings Limited | London | 1966 |
| Bakkavor Fresh Cook Limited | London | 2004 |
| Bakkavor Invest Limited | London | 2004 |
| Bakkavor Overseas Holdings Limited | London | 1971 |
| Bakke Anlegg Limited | London | 2023 |
| Bako North Western Limited | Preston | 2018 |
| Bako Northern (Holdings) Limited | Preston | 1998 |
| Bako Scotland Limited | Preston | 2003 |
| Bako South Eastern Limited | Preston | 2013 |
| Bako Zero 8 Ltd | Hampton | 2018 |
| BAL Property Management Ltd | Nottingham | 2016 |
| BAL Sail Ltd | London | 2024 |
| Bala Lettings London Limited | London | 2015 |
| Balaam Brothers Fencing Ltd | Sandy | 2011 |
| Balabio Ltd | Burgess Hill | 2023 |
| Balajee Spice Limited | Perth | 2016 |
| Balance Marketing Group Limited | Manchester | 2022 |
| Balance Mind Limited | Leeds | 2017 |
| Balance of Power Trading Limited | Tamworth | 2016 |
| Balance on Edges Ltd | Mitcham | 2024 |
| Balance REC Ltd | Mildenhall | 2019 |
| Balance Sheet Protectors Limited | Leeds | 2021 |
| Balance: Trustees Limited | Nottingham | 2016 |
| Balanced by Nature Ltd | Southampton | 2021 |
| Balanced Health Limited | London | 2008 |
| Balanced Horse Feeds Limited | Woking | 1989 |
| Balanced Solutions Ltd | Trowbridge | 2024 |
| Balancesentiments Ltd | Manchester | 2024 |
| Balaton-Maia Ltd | East Grinstead | 2012 |
| Balavoulin Ltd | Glasgow | 2023 |
| Balazs Mike Ltd | London | 2025 |
| Balbir Singh Madahar Ltd | Bilston | 2024 |
| Balby Power Limited | Newark | 2016 |
| Balchder Cymru CYF | Blackwood | 2019 |
| Balchins Close Management Limited | Wisborough Green | 2017 |
| Balckmir Co., Ltd | London | 2023 |
| Balcodeck Limited | Lingfield | 2024 |
| Balcones Limited | Nuneaton | 2012 |
| Balconette Limited | Lingfield, Blindley Heath | 2015 |