| Bartex Impro LP | | 2012 |
| Bartlow LP | | 2016 |
| Barto Living Ltd | Real estate | 2026 |
| Bartola Corporation | | 2009 |
| Bartoli Management LP | | 2016 |
| Bartolome DE LAS Casas LP | | 2013 |
| Barton & Davies (Jean Saloon) Limited | Real estate | 1972 |
| Barton & Hendry LLP | | 2021 |
| Barton Carlyle Analytics Limited | Administrative & support | 2015 |
| Barton Carlyle Limited | Administrative & support | 2009 |
| Barton Minerals LP | | 2013 |
| Barton Production LP | | 2016 |
| Barton Scotland Limited | Water & waste | 2001 |
| Barty Education and Development Limited | Administrative & support | 2022 |
| Baruby Ltd | Information & communication | 2023 |
| Barwood Regional Property Growth Fund V (Founder Partner GP) Limited | Financial services | 2022 |
| Barwood Regional Property Growth Fund V (Founder Partner) LP | | 2022 |
| Bas-Ip LP | | 2014 |
| Basalt Partners LP | | 2007 |
| Base Access Ltd | Professional & scientific | 2016 |
| Base Corporation LP | | 2014 |
| Base Element LP | | 2023 |
| Base Recovery Limited | Arts & recreation | 2025 |
| Base Spirits Ltd | Wholesale & retail | 2019 |
| Based Apps Ltd | Wholesale & retail | 2023 |
| Basedbuilders Holding LP | | 2023 |
| Basell Scottish Limited Partnership | | 2006 |
| Basenji LP | | 2004 |
| Basepoint Accountancy Services Ltd | Professional & scientific | 2010 |
| Bases Loaded Limited | Information & communication | 2011 |
| Bash Tyres Ltd | Wholesale & retail | 2025 |
| Bashir&Sons Ltd | Other services | 2025 |
| Basic Vending Limited | Wholesale & retail | 2022 |
| Basil Baird (Fareham) Limited | Agriculture & fishing | 1970 |
| Basil Paterson Limited | Education | 2000 |
| Basil Services L.P. | | 2012 |
| Basilico 2024 Ltd | Professional & scientific | 2024 |
| Basiliko Limited | Hospitality | 2024 |
| Basilk Limited | Administrative & support | 2025 |
| Basilshub Limited | Wholesale & retail | 2025 |
| Basitics PVT Limited | Wholesale & retail | 2025 |
| Basketballscotland Limited | Other services | 2005 |
| Basoma Property Limited | Real estate | 2023 |
| Bassaguard Garage Ltd. | Wholesale & retail | 1997 |
| Basset Hound LP | | 2004 |
| Bassett Corporation L.P. | | 2011 |
| Bassetterra LP | | 2016 |
| Bassira Ltd | Health & social care | 2022 |
| Bastin Sales and Services Holding LP | | 2024 |
| Bastnet Ltd | Information & communication | 2014 |
| Baston Trading LP | | 2013 |
| BAT Edinburgh Limited | Wholesale & retail | 2024 |
| Batgara Limited | Hospitality | 2025 |
| Bath Street Collective Custom Build Limited | Construction | 2014 |
| Bather Intergroup L.P. | | 2009 |
| Bathgate Dental Practice Ltd. | Health & social care | 2009 |
| Bathing Mobility Advisory Service Limited | Construction | 2005 |
| Bathmophobia Records Limited | Information & communication | 2020 |
| Bathroom Best Limited | Construction | 2010 |
| Bathurst Classics LP | | 2019 |
| Bathurst Property Assets LP | | 2020 |
| BATI1819 Ltd | Financial services | 2024 |
| Batis Books Limited | Information & communication | 2025 |
| Batis Ceramics Ltd | Manufacturing | 2024 |
| Batlow Commerce LP | | 2015 |
| Batra Property Holdings Limited | Financial services | 2026 |
| Batsela Capital Investments LP | | 2023 |
| Batten GAS Services Ltd | Construction | 2021 |
| Battery Point SP | | 2003 |
| Battilei Ltd | Hospitality | 2025 |
| Battista LP | | 2012 |
| Battista Property Ltd | Real estate | 2021 |
| Battistra Universal LP | | 2011 |
| Battlebox HQ Ltd | Manufacturing | 2017 |
| Battleboxuk Ltd | Construction | 2015 |
| BAU Hair Design Limited | Other services | 2017 |
| Bauditon Industries LP | | 2014 |
| Bauer LP | | 2014 |
| Bauer Radio's Cash for Kids Charities (Scotland) | Health & social care | 2010 |
| Baum UK Limited | Professional & scientific | 2002 |
| Baumont Core Plus General Partner One LLP | | 2022 |
| Baumont CPP One Co-Invest LP | | 2022 |
| Baumwolle Impex LP | | 2014 |
| Bautheac International LP | | 2020 |
| Bauwerk Intex LP | | 2011 |
| Bavaria Auto Werke Limited | Wholesale & retail | 2002 |
| Bavavu Ltd | Wholesale & retail | 2022 |
| Bavelaw Consultancy Ltd | Professional & scientific | 2023 |
| Baverder Ltd | Wholesale & retail | 2017 |
| Bawan Barber Limited | Other services | 2024 |
| BAX Trade LP | | 2017 |
| Baxendale Employee Ownership Trustees Limited | Other services | 2022 |
| Baxendale Limited | Extraterritorial | 2013 |
| Baxter Family Trustees Limited | Administrative & support | 2019 |
| Baxter Global LP | | 2014 |
| Baxter United LP | | 2013 |
| Baxters Food Group Limited | Manufacturing | 1945 |
| Bay Corporation L.P. | | 2012 |
| Bay Leaf and Cinnamon Ltd | Hospitality | 2019 |
| Baycloud Limited | Professional & scientific | 1993 |