| Budget Print Ltd | Westcliff-On-Sea | 2011 |
| Budget Self Storage Limited | Matlock | 2010 |
| Budget Storage Newcastle Limited | Newcastle Upon Tyne | 2016 |
| Budleigh Salterton Information Centre CIC | Budleigh Salterton | 2007 |
| Budo Trade Ltd | Carcroft | 2011 |
| Buds & Beaus Ltd | Mildenhall | 2025 |
| Buds Doggy Day Care Ltd | Ashford | 2021 |
| Budworth Wellness Ltd | Prenton | 2026 |
| BUE Marine Limited | Edinburgh | 1991 |
| Buef Ltd | London | 2025 |
| Buena Onda Advertising Ltd | Cardiff | 2022 |
| Bueno Salon Ltd | Upton | 2025 |
| Buer Ltd | Polegate | 2024 |
| Buettners Ltd | London | 2024 |
| Buff & Bare Hitchin Limited | Dartmouth | 2026 |
| Buff & Bare Ltd | Dartmouth | 2018 |
| Buff & Polish Ltd | London | 2015 |
| Buff and Beauty Ltd | Penryn | 2025 |
| Buff and Shine Ltd | London | 2016 |
| Buff Concept Store Limited | Edinburgh | 2016 |
| Buff Hair & Beauty Ltd | London | 2006 |
| Buff London Ltd | London | 2018 |
| Buff Urban Day Spa Limited | Taunton | 2007 |
| Buffallo Holdings Ltd | London | 2025 |
| Buffalo Associates Limited | Preston | 2013 |
| Buffalo Gardening Limited | West Drayton | 2025 |
| Buffalo Lodge Retreat Ltd | Leighton Buzzard | 2023 |
| Buffalo Mindset Limited | Prescot | 2018 |
| Buffbar Limited | Potters Bar | 2023 |
| Buffbay Limited | Eastleigh | 2014 |
| Buffrail Limited | Kidderminster | 2000 |
| Buffs Hair & Beauty Bar Limited | Benfleet | 2018 |
| Buffy Limited | Bristol | 2006 |
| Bufton Lending Ltd | Little Ellingham | 2018 |
| Bugajewski Ltd | Gateshead | 2015 |
| Bugarashar Ltd | London | 2021 |
| Buggy PIT Stop Ltd | Pinner | 2013 |
| Buggy Pitstop Partners Ltd | London | 2024 |
| Bugra Ltd | London | 2009 |
| Bugs 'N' Things Pest Control Ltd | Arlesey | 2003 |
| Bugs and Bytes Computing Ltd | Lincoln | 2020 |
| Bugsy Holdings Limited | Northampton | 2023 |
| Buho Azul Ltd | Derby | 2023 |
| Buho Group Limited | Leeds | 2016 |
| BUI & SON Limited | Southampton | 2023 |
| BUI Enterprise Limited | London | 2015 |
| Buiildsafe (UK) Ltd | Plymouth | 2018 |
| Build a Beauty Limited | London | 2023 |
| Build a Haven Ltd | London | 2020 |
| Build and Maintain Limited | East Dulwich | 2008 |
| Build and Ventilation Ltd | London | 2023 |
| Build Assistant Ltd | Preston | 2017 |
| Build Gold Limited | Basildon | 2024 |
| Build Innovatives Ltd | Smethwick | 2021 |
| Build JB Ltd | Brighouse | 2017 |
| Build London Atoz Limited | Ilford | 2019 |
| Build Manhattan Ltd | Romford | 2024 |
| Build Pros Agency Limited | Basildon | 2024 |
| Build Safe Building Control Limited | Great Dunmow | 2024 |
| Build Scotland Ltd | Edinburgh | 2020 |
| Build the Bandwagon Ltd | Harrogate | 2021 |
| Build to Serve Ltd | Bilston | 2016 |
| Build UK Group Limited | London | 2015 |
| Build X for Investment Ltd | Manchester | 2021 |
| Build Your Temple (B.Y.T) Prayer Ministries | Coventry | 2010 |
| Buildaballergym Ltd | Bury | 2026 |
| Buildbrighton | Brighton | 2010 |
| Builders Cleaners Ltd | Swindon | 2014 |
| Builders Direct Ltd | Middlesbrough | 2026 |
| Builders of Business Ltd | Middlesbrough | 2025 |
| Buildgrowlast Ltd | St. Albans | 2023 |
| Building 1 Zone Limited | St. Albans | 2015 |
| Building 13 Ltd | Bristol | 2015 |
| Building and Garden Services Limited | West Midlands | 2003 |
| Building and Handyman Fulham Limited | Sutton | 2011 |
| Building and Racing a Legend.Com Ltd | Morden | 2017 |
| Building Better Relationships Ltd | Sevenoaks | 2011 |
| Building Blocks G B Limited | Swansea | 2018 |
| Building Brands Marketing Ltd | Plymouth | 2025 |
| Building Bridges for Unity | Brighouse | 2015 |
| Building Church Limited | Bradford | 2016 |
| Building Cladding & Safety Scheme Advisors Ltd | Loughton | 2025 |
| Building Coatings Ltd | Paisley | 2018 |
| Building Construction Management Ltd | Bexleyheath | 2015 |
| Building Controls Industry Association Limited | Hare Hatch, Reading | 2023 |
| Building Critical Excellence Alliance Limited | London | 2026 |
| Building Empire Ltd | Wembley | 2012 |
| Building Estimates Ltd | Reading | 2023 |
| Building for Growth Limited | Widmer End | 2023 |
| Building Future Leaders Ltd | Nottingham | 2021 |
| Building Futures East Limited | Newcastle Upon Tyne | 2007 |
| Building Hope Ltd | Hemel Hempstead | 2026 |
| Building Management Technology Limited | Syston | 2011 |
| Building ME | Holywood | 2019 |
| Building Performance Ltd | Walsall | 2019 |
| Building Response Limited | London | 2012 |
| Building Right Relationships Ltd | Cardiff | 2019 |
| Building Safety and Fire Ltd | Hornchurch | 2023 |
| Building Safety Competence Foundation C.I.C. | London | 2021 |
| Building Solutions (North London) Limited | London | 2016 |