| Barberry Securities Limited | Stourbridge | 1995 |
| Barbican Holdings Limited | York | 2004 |
| Barbican Refreshments UK Ltd | London | 2021 |
| Barbour Threads Limited | Glasgow | 1919 |
| Barbridge Flyover Company Ltd | London | 2002 |
| Barbryn Limited | Birmingham | 1978 |
| Barch Motion Technology Co., Ltd | London | 2016 |
| Barclay Communications Group Limited | Belfast | 2023 |
| Barclay Gifford Associates Limited | Colchester | 2002 |
| Barclay Group Limited | Bromley | 2000 |
| Barclay Property Co Limited | Nottingham | 2017 |
| Barclay SMS Limited | Leamington Spa | 2019 |
| Barclays Shea Limited | London | 2010 |
| Barclays Woollen Co.Limited | | 1938 |
| Barco Amber Limited | Blackpool | 2019 |
| Barcroft Media Limited | Bath | 2003 |
| Bard Bidco Limited | London | 2020 |
| Bard Studio Ltd | Glasgow | 2015 |
| Bard Tutoring Ltd | Wokingham | 2013 |
| Barden Audio Systems Limited | Robertsbridge | 2011 |
| Bardfields Estate Management Company Limited | Leigh-On-Sea | 1999 |
| Bardle Group Limited | Kingston Upon Hull | 2022 |
| Bardophonics Limited | Hatfield | 2009 |
| Bardrift Levanger Limited | London | 2009 |
| Bardwell Business Enterprises Limited | Sheffield | 2014 |
| Bardwell Homes Ltd | Chelmsford | 2016 |
| Bare Competitions Ltd | Bristol | 2024 |
| Bare Gigs Limited | Moreton-In-Marsh | 2009 |
| Bare GLO Ltd | Plymouth | 2025 |
| Barefoot Healing Limited | Chelmsford | 2021 |
| Barefoot MAN Ltd | Milton Keynes | 2023 |
| Barefoot Renovations Limited | Cuckfield | 2017 |
| Bareham Limited | London | 2012 |
| Barents Sea Fish Limited | Bishop Auckland | 2015 |
| Baretrading Limited | Kettering | 2023 |
| Barfive Limited | Fishguard | 2002 |
| Barfoot Holdings Limited | Bognor Regis | 2001 |
| Barford Site Dumpers Ltd | Bourne | 2010 |
| Bargain Basement Centre Limited | Watford | 2006 |
| Bargain Hive Ltd | Nottingham | 2022 |
| Bargain Home Essentials Ltd | Huddersfield | 2024 |
| Bargain Parking Limited | London | 2011 |
| Bargainphv Ltd | London | 2016 |
| Bargainry Limited | Otley | 2024 |
| Barge Bakery and Cafe Ltd | Romney Marsh | 2013 |
| Barham Court Limited | Leicester | 2015 |
| Bariatric & Obesity Advisors Ltd | Staines | 2024 |
| Baric Pumps Limited | Manchester | 2003 |
| Baricca Limited | Uxbridge | 2020 |
| Baring Road RTM Company Limited | London | 2012 |
| Bark Hotel Ltd | Pontyclun | 2022 |
| Bark Timber Frame Design Ltd | Burnley | 2022 |
| Bark to the Future Ltd | Hyde | 2026 |
| Barkath Foods (U.K.) Limited | Southport | 1973 |
| Barkemp Groundworks Limited | Aylesford | 2013 |
| Barker & Co Accountancy Services Ltd | Derbyshire | 2007 |
| Barker & Hird Limited | Colchester | 1989 |
| Barker and Bass Limited | Kettering | 2011 |
| Barker Butts Lane Management Company Limited | High Wycombe | 2007 |
| Barker Consulting Ltd | Clitheroe | 2019 |
| Barker Events Ltd | London | 2016 |
| Barker James Limited | Sudbury | 2017 |
| Barker Safety Services Ltd | Wisbech | 2025 |
| Barker Wilson Limited | Cardiff | 2026 |
| Barkers Road Poultry Limited | Newry | 2025 |
| Barking Brickwork Limited | Westcliff On Sea | 2014 |
| Barking Buddys Ltd | Worthing | 2015 |
| Barking MAD Creations Limited | York | 2008 |
| Barking Shopfitters Limited | Ilford | 2005 |
| Barklay Holdings Ltd | Lichfield | 2018 |
| Barkley Estates Limited | Mansfield | 2016 |
| Barklife Limited | Slough | 2015 |
| Barkmere Limited | Bridgend | 2026 |
| Barko Decor Ltd | Beckenham | 2014 |
| Barks and Brambles Ltd | Thirsk | 2025 |
| Barkston Plastics Forming Limited | Leeds | 1991 |
| Barley Construction Limited | Bromley | 2009 |
| Barley Construction Management Limited | Bromley | 2001 |
| Barleys Limited | Bognor Regis | 2013 |
| Barleys Yard 1958 Limited | Thirsk | 2013 |
| Barleyseed Limited | London | 2008 |
| Barleysmith Brewing Company Ltd | Congleton | 2021 |
| Barlings Limited | Newark | 1997 |
| Barlow Bright Steels | Nottingham | 1935 |
| Barlow Business Support Ltd | Newport | 2017 |
| Barloworld Handling Limited | London | 1956 |
| Barlows Alarms Limited | Malpas | 1989 |
| Barmac Asset Management Limited | Leeds | 2004 |
| Barmada Limited | London | 2021 |
| Barmy Education Limited | Blackburn | 2017 |
| Barn & Brook of Moreton-In-Marsh Ltd | Moreton-In-Marsh | 2017 |
| Barn Anthology Ltd | Cirencester | 2019 |
| Barn Babies (Thaxted) Limited | Dunmow | 2000 |
| Barn Holt Limited | Horncastle | 2008 |
| Barn Living Gifts Limited | Totnes | 2020 |
| Barn Meadow Green Limited | Leatherhead | 2010 |
| Barn Medical Group Limited | Oswestry | 2025 |
| Barn Publishing Limited | London | 1971 |
| Barn SPV 2 Limited | Cirencester | 2023 |
| Barna Imports Limited | Manchester | 2015 |