| Big Sky Construction Ltd | Construction | 2018 |
| Big Sky Developments Ltd | Construction | 2013 |
| Big Sky Investments Ltd | Real estate | 2002 |
| Big Sky Living Ltd | Real estate | 2024 |
| Big Sky Property Management Ltd | Real estate | 2014 |
| Big Sky Ventures Ltd | Professional & scientific | 2014 |
| Big T Fitness Limited | Financial services | 2022 |
| Big T'S Roofing & Building Ltd | Construction | 2025 |
| Big Week Consulting Limited | Professional & scientific | 2024 |
| Big Wood Fisheries Limited | Agriculture & fishing | 2009 |
| Bigbonk Studio Limited | Information & communication | 2026 |
| Bigdaddypr Limited | Administrative & support | 2015 |
| Bigfork Limited | Information & communication | 2010 |
| Bigg SAJ Pizza Ltd | Hospitality | 2022 |
| Bigger Bars Ltd | Hospitality | 2018 |
| Bignold Management Company Limited | Households | 2023 |
| Bigphatphotos Limited | Professional & scientific | 2012 |
| BIH Wreningham Limited | Extraterritorial | 2015 |
| Bike "TU" BUS Ltd | Transport & logistics | 2016 |
| Bilash (Knowle) Limited | Hospitality | 2012 |
| Bilateral Base Ltd | Manufacturing | 2018 |
| Bilbilev Ltd | Transport & logistics | 2022 |
| Bill Kenny Developments Limited | Construction | 2020 |
| Billie's Pantry Ltd | Hospitality | 2019 |
| Billingham Engineering Limited | Professional & scientific | 2007 |
| Billsavvy Ltd | Administrative & support | 2013 |
| Billy Hill Communications Ltd | Professional & scientific | 2025 |
| Billy's Coffee House Ltd | Hospitality | 2025 |
| Bilton Fish Bar Limited | Hospitality | 2019 |
| Bilton Salons Limited | Other services | 2017 |
| Bilubu Limited | Administrative & support | 2018 |
| Bimota UK Limited | Wholesale & retail | 2021 |
| BIN Refresh Ltd | Administrative & support | 2025 |
| Binary Chain Ltd | Information & communication | 2017 |
| Bind Yoga Ltd | Arts & recreation | 2018 |
| Binding Store Limited | Wholesale & retail | 2006 |
| Binejoshmark(Bjm) Limited | Professional & scientific | 2015 |
| Binqua Limited | Information & communication | 2010 |
| BINS2FRESH Ltd | Administrative & support | 2025 |
| Binum Devices Limited | Wholesale & retail | 2019 |
| Binx & BOO Natural Ltd | Wholesale & retail | 2025 |
| Binx and BOO Wholesale Ltd | Wholesale & retail | 2026 |
| Bioarmor International Ltd | Manufacturing | 2013 |
| Biodiversity NET Gain East Anglia Ltd | Agriculture & fishing | 2024 |
| Bioscopic Limited | Professional & scientific | 2023 |
| Bioskin Consulting Limited | Other services | 2012 |
| Biosphere Expeditions Limited | Health & social care | 2000 |
| Biotransitions Ltd | Extraterritorial | 2025 |
| Bioventure Development Limited | Professional & scientific | 2009 |
| Bioventure Limited | Extraterritorial | 2009 |
| Bioventure Medical Innovations Ltd | Extraterritorial | 2012 |
| Biovista Sciences Limited | Extraterritorial | 2008 |
| Birbeck Way Residents Association (1986) Limited | Households | 1986 |
| Birch Property Investments Limited | Real estate | 2015 |
| Birch Tree Construction Ltd | Construction | 2018 |
| Birch&S Training Limited | Education | 2026 |
| Birchcam Limited | Administrative & support | 2025 |
| Birchvale Properties Limited | Real estate | 2002 |
| Birchway Woods Limited | Real estate | 2024 |
| Birchwood EA Limited | Health & social care | 2010 |
| Birchwood Energy Limited | Professional & scientific | 2014 |
| Birchwood [Conservatories] Limited | Wholesale & retail | 2002 |
| Birdflight Investments Ltd | Administrative & support | 2005 |
| Birding Ecotours Limited | Administrative & support | 2019 |
| Birdsoup Ltd | Professional & scientific | 2016 |
| Birketts Building Management Company Limited | Households | 2003 |
| Birmingham Mithai Ghor Limited | Hospitality | 2018 |
| Birmingham VEG Restaurant Ltd | Hospitality | 2025 |
| Birth Revolution Ltd. | Wholesale & retail | 2023 |
| Birthrate Plus Associates Limited | Administrative & support | 2014 |
| Birtwhistle Ltd | Professional & scientific | 2022 |
| Bishop Auckland 3 LLP | | 2013 |
| Bishop Bridge Court Management Limited | Households | 1987 |
| Bishop Builders Ltd | Construction | 2016 |
| Bishop's Close Residents Association Limited | Households | 2005 |
| Bishop's Gate Studios Limited | Information & communication | 2013 |
| Bishopgate Capital Limited | Other services | 2025 |
| Bishops Court (Sprowston) Management Company Limited | Real estate | 2003 |
| Bishopsgate Nominees Limited | Financial services | 2019 |
| Bishy B Industries Limited | Information & communication | 2006 |
| Bishy Baconbee Ltd | Hospitality | 2024 |
| Bishy Barnaby Estates Ltd | Real estate | 2026 |
| Bishy Boats Ltd | Other services | 2024 |
| BIT Sounds Ltd | Information & communication | 2019 |
| Bite and Smile Limited | Health & social care | 2020 |
| Bite the Cherry Limited | Professional & scientific | 2016 |
| Bitefirst Limited | Information & communication | 2014 |
| Bittern Breaks Ltd | Real estate | 2025 |
| Bixley House and BER House Residents Association Limited | Professional & scientific | 2003 |
| BIZ Dynamics Ltd | Wholesale & retail | 2021 |
| Bizclik Media Group Limited | Administrative & support | 2020 |
| Bizclik Media Limited | Information & communication | 2007 |
| Bizfin Solutions Ltd | Professional & scientific | 2023 |
| Biziamo Software Limited | Information & communication | 2013 |
| BJC Caravans Limited | Hospitality | 2024 |
| BJC Construction Projects Ltd | Construction | 2020 |
| BJC Developments Limited | Construction | 2021 |
| BJD Adamsons Limited | Professional & scientific | 2011 |
| Bjets UK Ltd | Administrative & support | 2024 |
| BJJ in Norwich Ltd | Education | 2019 |