| Birmingham Industrial Therapy Association Limited | Birmingham | 1963 |
| Birmingham Joinery Limited | Birmingham | 2002 |
| Birmingham Kitchens&Bedrooms Ltd | Birmingham | 2024 |
| Birmingham Mailing Cases Limited | Erdington | 1923 |
| Birmingham Optical Group Limited | Birmingham | 1972 |
| Birmingham Orthotic Services Ltd | Tipton | 2019 |
| Birmingham Powder Coatings Limited | Portsmouth | 1996 |
| Birmingham Precision Engineering Limited | Matlock | 2012 |
| Birmingham Railway Carriage & Wagon Company Limited | Marston Green | 2014 |
| Birmingham RAW Pet Food Limited | Birmingham | 2020 |
| Birmingham Safety Wear Limited | Birmingham | 2007 |
| Birmingham SAW Blades Limited | Stourbridge | 1972 |
| Birmingham Sealed Units Ltd | Birmingham | 2022 |
| Birmingham Specialities Limited | Birmingham | 1928 |
| Birmingham Stamping Ltd | Farnham | 2023 |
| Birmingham Steel Limited | Smethwick | 2021 |
| Birmingham Stone Cutting Company Limited | Birmingham | 1966 |
| Birmingham Stopper Limited | Birmingham | 1997 |
| Birmingham Transformers Limited | Birmingham | 1995 |
| Birmingham Truck and Trailer Repairs Limited | Birmingham | 2019 |
| Birmingham Underground Structures Limited | Birmingham | 2022 |
| Birmingham Veneers Limited | Birmingham | 2010 |
| Birmingham Welding Supplies Limited | Birmingham | 2001 |
| Birmingham Windscreens Ltd. | Henley-In-Arden | 1976 |
| Birmstoke Limited | Birmingham | 2021 |
| Biro Medical Ltd | Gloucester | 2025 |
| Birou Transport Ltd | Birmingham | 2022 |
| Birson Property Company Limited | Aylesbury | 1987 |
| Birstall Foundry Company Limited | Slough | 1959 |
| Birt & Tang Ltd | Orpington | 2002 |
| Birthing Solutions Limited | Edinburgh | 2017 |
| Birthjuly Ltd | Kington | 2025 |
| Birtle & Co. Kitchens and Furniture Ltd | Alpington | 2021 |
| Birtles & Co Cleaning Services Ltd | Penrith | 2026 |
| Birtles Solutions Ltd | Northwich | 2023 |
| Birtley Group Limited | Solihull | 1958 |
| Birton Valentin-Mihai Ltd | Stoke-On-Trent | 2016 |
| Birtwell & Co.Limited | Accrington | 1960 |
| Birtwisejewls Ltd | London | 2025 |
| BIS Shavings Ltd | Birmingham | 2024 |
| BIS Valves Limited | Wimborne Dorset | 1964 |
| Bisade Cake Atelier Ltd | Croydon | 2025 |
| Bisbaas Sauce Ltd | Liverpool | 2022 |
| Bisbell Magnetic Products Limited | Wednesbury | 1971 |
| Bisca UK Limited | Helmsley | 2009 |
| Bischof & Klein (UK) Limited | Telford | 1978 |
| Bischoff Ltd | London | 2025 |
| Biscoat Bakery Ltd | Edinburgh | 2026 |
| Biscone Bakery Ltd | Barrow-In-Furness | 2026 |
| Biscor Limited | Heywood | 1976 |
| Biscot Motors Ltd | Luton | 2018 |
| Biscottilicious Ltd | London | 2018 |
| Biscuit Boutique Limited | Barnet | 2019 |
| Biscuit International (UK) II Limited | Gateshead | 1997 |
| Biscuit International UK Limited | Gateshead | 2002 |
| Biscuit JIM Ltd | London | 2024 |
| Biscuit Lane Limited | London | 2025 |
| Biscuiteer Baking Company Ltd | London | 2007 |
| Biscuiteers Limited | London | 2025 |
| BISERVICES511 Ltd | Wirral | 2022 |
| Bisgedi Enterprises Limited | Leigh | 2024 |
| Bish Bash Bosh Food Limited | Mildenhall | 2025 |
| Bishey Ltd | London | 2021 |
| Bishop Carpentry Ltd | Manchester | 2022 |
| Bishop Embellishments Limited | Burnley | 2017 |
| Bishop Engineering Limited | West Midlands | 2000 |
| Bishop Interiors Ltd | Warrington | 2022 |
| Bishop Media Walls Limited | Warrington | 2025 |
| Bishop Nick Limited | Braintree | 2011 |
| Bishop's Beds Ltd | Peterlee | 2005 |
| Bishop's Crook Brewery Ltd. | Preston | 2013 |
| Bishoprise Limited | Wolverhampton | 2012 |
| Bishops & Haig Limited | Crawley | 2026 |
| Bishops Court Editions Ltd | Axminster | 2019 |
| Bishops Joinery Limited | Southampton | 2005 |
| Bishops Palace Ltd | London | 2024 |
| Bishops Park Group Ltd | Exeter | 2024 |
| Bishops Printers Limited | Portsmouth | 1992 |
| Bishopsgate Distillery & Wine Company Limited | Princes Risborough | 2005 |
| Bishopsound Manufacturing and Design Limited | Ripon | 2021 |
| Bisi Ltd | London | 2020 |
| Biskit Controls Limited | Stirling | 2010 |
| Biskol Services Limited | Dagenham | 1999 |
| Biskut Bar Limited | London | 2020 |
| Bismillah Enterprise Ltd | Bradford | 2020 |
| Bismillah Poultry Ltd | Birmingham | 2025 |
| Bisn Holdings Limited | Warrington | 2014 |
| Bisn OIL Tools Ltd | Warrington | 2011 |
| Bisn TEC Ltd. | Warrington | 2008 |
| Bisng Limited | London | 2025 |
| Bison Bede Limited | Bradford | 1998 |
| Bison Engineering & Construction Ltd | Ledbury | 2014 |
| Bison Engineering Services (UK) Ltd | Kingswinford | 2019 |
| Bison Fabrications Ltd | Wakefield | 2013 |
| Bison Frames (UK) Limited | Barnsley | 2002 |
| Bison Ibc's Limited | Blidworth | 1999 |
| Bison Inc Ltd | Gateshead | 2012 |
| Bison Life UK Limited | London | 2023 |
| Bison Orthopaedics Ltd | Wirral | 2025 |
| Bison Power Ltd | Leeds | 2026 |