| Balmoraltech Limited | Information & communication | 2025 |
| Balnacoil Farming Limited | Agriculture & fishing | 2007 |
| Balnoon Wind Limited | Energy | 2015 |
| Baloshi Brothers Construction Ltd | Construction | 2018 |
| Balsam Energy (UK) Services Limited | Wholesale & retail | 2024 |
| Baltic Bounties Ltd | Arts & recreation | 2024 |
| Baltyk Delicatessen Limited | Wholesale & retail | 2024 |
| Baltyk Delicatessen Store Ltd | Wholesale & retail | 2025 |
| Bama Dreamline Ltd | Manufacturing | 2025 |
| Bamako LP | | 2013 |
| Bambini Ltd. | Administrative & support | 1995 |
| Bamma Investments Limited | Professional & scientific | 2009 |
| Bamma Properties Limited | Construction | 2008 |
| Banaras Bazaar Ltd | Wholesale & retail | 2025 |
| Banbury Cross Nursery Limited | Education | 2011 |
| Banchory Lodge Ltd. | Administrative & support | 2011 |
| Bandit Bakery Ltd | Manufacturing | 2019 |
| Baneen Mart Ltd | Wholesale & retail | 2025 |
| Banff Airfield Trust | Professional & scientific | 2010 |
| Banffshire Fishselling Company Limited | Professional & scientific | 1973 |
| Bankhead Control Systems Ltd | Manufacturing | 2023 |
| Bankhead Electrical Services Limited | Manufacturing | 2016 |
| Banks O'Dee Sports Club Limited | Arts & recreation | 1997 |
| Banman Holdings Ltd | Real estate | 2022 |
| Bannerman Bathrooms Ltd | Construction | 2025 |
| Bannerman Projects Limited | Mining & quarrying | 2025 |
| Banotop Energy Services Ltd | Professional & scientific | 2009 |
| Bar Bumble Ltd | Hospitality | 2022 |
| Bar Enterprise ABZ Limited | Hospitality | 2024 |
| Bar-Tek Acoustics Limited | Manufacturing | 2017 |
| Baramech Consulting Limited | Professional & scientific | 2026 |
| Barbados Network LP | | 2014 |
| Barclay Offshore Services Ltd | Professional & scientific | 2019 |
| Barclay Power Solutions Limited | Wholesale & retail | 2015 |
| Barclay Pubs Ltd | Hospitality | 2021 |
| Barco Leisure Ltd | Real estate | 2024 |
| Barco Pubs Ltd | Hospitality | 2021 |
| Bardi Design Services Limited | Mining & quarrying | 2006 |
| Bare Clinical Spmu Ltd | Other services | 2026 |
| Barefoot and Twisted Yoga Limited | Health & social care | 2015 |
| Barletta Inter LP | | 2013 |
| Barmonte Properties Ltd | Real estate | 2012 |
| Barnes Group Inc Limited | Hospitality | 2024 |
| Barpub Limited | Hospitality | 2019 |
| Barra Energy Limited | Mining & quarrying | 2015 |
| Barraigh Capital Management Limited | Administrative & support | 2010 |
| Barramac Engineering Limited | Professional & scientific | 2022 |
| Barreleye Ltd | Information & communication | 2023 |
| Barreto Consulting Ltd | Administrative & support | 2025 |
| Baryksdent Services Limited | Health & social care | 2013 |
| Bask Engineering Consulting Ltd. | Professional & scientific | 2013 |
| Bass Terre LP | | 2013 |
| Bast Crystals Ltd | Wholesale & retail | 2022 |
| Basttech Ltd | Professional & scientific | 2023 |
| Batigea Ltd | Professional & scientific | 2018 |
| Batmax Consult Limited | Professional & scientific | 2016 |
| Battery Terotech Limited | Manufacturing | 2000 |
| Battlecove Limited | Professional & scientific | 2008 |
| Baubled Ltd | Wholesale & retail | 2021 |
| Baux UK Ltd | Professional & scientific | 2026 |
| Bavaria Auto-Motor Werke Limited | Wholesale & retail | 2024 |
| Bavur I&M Trading Limited | Wholesale & retail | 2025 |
| Baxel Limited | Real estate | 1981 |
| Bay Consulting Scotland Ltd | Professional & scientific | 2022 |
| Bay Ridge Properties Limited | Administrative & support | 2012 |
| Bayani Ltd | Wholesale & retail | 2015 |
| Baynur Group Ltd | Transport & logistics | 2024 |
| Bayview Group Limited | Real estate | 2022 |
| Baywatch Developments Limited | Real estate | 1995 |
| Bazan Inspection Limited | Professional & scientific | 2022 |
| Baztech Ltd | Mining & quarrying | 2011 |
| BB Minto Limited | Real estate | 2022 |
| BB Projects Ltd | Mining & quarrying | 2014 |
| BBL Downhole Tools Limited | Professional & scientific | 1998 |
| BBN Agency X Limited | Professional & scientific | 2023 |
| Bccvending Limited | Wholesale & retail | 2013 |
| BCD219 Limited | Professional & scientific | 2006 |
| BCI Industrial Services Limited | Professional & scientific | 2018 |
| BCK Food Ltd | Hospitality | 2017 |
| BCS Engineering Ltd | Professional & scientific | 2013 |
| Bcsc Rock Limited | Financial services | 2024 |
| BCT Anaesthetics Limited | Health & social care | 2022 |
| BD Trend Optic Ltd | Construction | 2023 |
| Bdellium Ltd | Professional & scientific | 2019 |
| BDJ Investments Limited | Real estate | 2026 |
| BDM Software Engineering Ltd | Information & communication | 2019 |
| Bdon Limited | Mining & quarrying | 2022 |
| BE Bare Limited | Wholesale & retail | 2018 |
| BE224 Ltd | Wholesale & retail | 2025 |
| Beach Aberdeen Ltd | Hospitality | 2024 |
| Beach Tree Catering Limited | Hospitality | 2018 |
| Beachdaze Limited | Real estate | 2022 |
| Beachstamp Limited | Real estate | 2009 |
| Beacon Finance Brokers Ltd | Financial services | 2026 |
| Beacon of Hope by LP Eunice CIC | Health & social care | 2025 |
| Bead Biopharma Limited | Professional & scientific | 2023 |
| Beamarr Property Ltd | Real estate | 2023 |
| Beannachar Limited | Education | 1987 |
| Beannie Services Ltd | Professional & scientific | 2012 |
| Bear Handling Limited | Other services | 2005 |