| Big Mountain Learning Ltd | Administrative & support | 2020 |
| Big Pockets Limited | Wholesale & retail | 2012 |
| Big Shed Enterprises Limited | Administrative & support | 2009 |
| Big Sho'Z Ltd | Hospitality | 2023 |
| Big Tasty's Catering Ltd | Hospitality | 2026 |
| Big Tree Consult Ltd | Real estate | 2022 |
| Big Valley Group Limited | Health & social care | 2017 |
| Big Vans Services Ltd | Transport & logistics | 2026 |
| Big Wide Grin Limited | Extraterritorial | 2020 |
| Big Y Steps Ltd | Construction | 2017 |
| Big Yawn Media Ltd | Information & communication | 2024 |
| BIG8 Consulting Ltd | Professional & scientific | 2022 |
| Bigame Limited | Health & social care | 2019 |
| Bigbearpromo Ltd | Administrative & support | 2021 |
| BIGG15 Ltd | Wholesale & retail | 2026 |
| Biggbeauty Ltd | Wholesale & retail | 2022 |
| Bigger Digital Ltd | Information & communication | 2018 |
| Bigold Associates UK Limited | Wholesale & retail | 2019 |
| Bigredbox Ltd | Information & communication | 2019 |
| Bigredbox Properties Ltd | Real estate | 2023 |
| Bigstep Enterprize Ltd | Information & communication | 2006 |
| Bijal Jewellers Limited | Wholesale & retail | 2014 |
| Bijal Limited | Health & social care | 2022 |
| Bikdrive Ltd | Transport & logistics | 2025 |
| Bike Spares R US Limited | Wholesale & retail | 2012 |
| Bike-Aquablasting Ltd | Wholesale & retail | 2016 |
| Bikeiconics Limited | Wholesale & retail | 2019 |
| Bikergearz Ltd | Wholesale & retail | 2016 |
| Bikram Yoga Leicester Ltd | Arts & recreation | 2019 |
| Bikram Yoga Loughborough Ltd | Education | 2020 |
| Bilal Fazmeer Limited | Wholesale & retail | 2026 |
| Bilal Hajj & Umrah Tours Ltd | Administrative & support | 2003 |
| Bilal Manufacturing Limited | Manufacturing | 2024 |
| Bilborough Logistics Ltd | Transport & logistics | 2014 |
| Bildmak Ltd | Professional & scientific | 2020 |
| Bilimoria Consulting Ltd | Professional & scientific | 2020 |
| Bill DID IT Ltd | Construction | 2025 |
| Billa AA Ltd | Wholesale & retail | 2025 |
| Billa Uppingham Leics Ltd | Wholesale & retail | 2025 |
| Billash Ltd | Wholesale & retail | 2024 |
| Billcoe PV Ltd | Other services | 2024 |
| Billie Care Limited | Health & social care | 2014 |
| Billiewise Solutions Ltd | Professional & scientific | 2024 |
| Billings Limited | Information & communication | 2008 |
| Billionaire Consultancy Ltd | Professional & scientific | 2018 |
| Billtech Consultancy Ltd | Information & communication | 2011 |
| Billy Bates & Sons Leisure Limited | Arts & recreation | 1990 |
| Billy Pram Ltd | Wholesale & retail | 2025 |
| Billy's Fish Bar (P P) Ltd | Hospitality | 2006 |
| Bill’S Equipment Limited | Hospitality | 2025 |
| Bilsington Legendary Ltd | Construction | 2015 |
| Bilton Logistics Ltd | Transport & logistics | 2014 |
| Bimmer Tech Limited | Wholesale & retail | 2024 |
| BIN Mattar Limited | Health & social care | 2022 |
| BIN Tami Ltd | Real estate | 2025 |
| BIN Zayed Investments Ltd | Professional & scientific | 2021 |
| Bin-Pro Ltd | Administrative & support | 2025 |
| Bindery Leathers UK Ltd | Wholesale & retail | 2018 |
| Bingham Kebabs Ltd | Hospitality | 2024 |
| Binghams CB Limited | Real estate | 2015 |
| Binghams GT Limited | Real estate | 2015 |
| Binning Haulage Limited | Transport & logistics | 2023 |
| Bino Systems Ltd | Construction | 2025 |
| Binster Properties Limited | Real estate | 1969 |
| Bio-Medical Laboratory Supplies Limited | Administrative & support | 2005 |
| BIO2CARBON Limited | Energy | 2016 |
| Biodex Trade Solutions Ltd | Construction | 2020 |
| Bioglobe Ltd | Professional & scientific | 2023 |
| Biomass Maintenance Limited | Professional & scientific | 2013 |
| Biomass Solutions Limited | Professional & scientific | 2008 |
| Bioresponse Solutions Limited | Administrative & support | 2024 |
| Bioscan Technologies Ltd | Professional & scientific | 2024 |
| Bioscent Ltd | Wholesale & retail | 2020 |
| Biotech Labs Ltd | Wholesale & retail | 2024 |
| Biovenix Limited | Wholesale & retail | 2025 |
| Bioxhale Ltd | Professional & scientific | 2021 |
| Birch Green Care Centre Limited | Health & social care | 2000 |
| Birch Motorsport Limited | Extraterritorial | 2025 |
| Birch Properties & Investment Ltd | Real estate | 2026 |
| Birchenall Couriers Ltd | Transport & logistics | 2017 |
| Birchfield(Uk) Limited | Real estate | 2020 |
| Birchlands (Haxby) Limited | Health & social care | 2014 |
| Birchmoor Developments Ltd. | Real estate | 2004 |
| Bircotes Logistics Ltd | Transport & logistics | 2014 |
| Bird and Howes LLP | | 2017 |
| Bird Property Management Limited | Real estate | 2022 |
| Bireddy Ltd | Construction | 2025 |
| Biring & Sons Properties Limited | Real estate | 2021 |
| Birmetals Limited | Professional & scientific | 1936 |
| Birmingham Business Park 2420 Limited | Real estate | 2025 |
| Birstall Automotive Ltd | Wholesale & retail | 2023 |
| Birstall Cabs Ltd | Transport & logistics | 2013 |
| Birstall Cars Ltd | Transport & logistics | 2015 |
| Birstall Construction Ltd | Construction | 2020 |
| Birstall Decorators Ltd | Construction | 2021 |
| Birstall Heating & Plumbing Ltd | Construction | 2025 |
| Birstall Holdings Ltd | Wholesale & retail | 2016 |
| Birstall Homes Ltd | Real estate | 2020 |
| Birstall Mini Market Ltd | Wholesale & retail | 2024 |
| Birstall Spice Limited | Hospitality | 2025 |