| Belash Uplands Ltd | Hospitality | 2026 |
| Belgrave Dental Centre Ltd | Health & social care | 2008 |
| Belkis Lifecoaching Ltd | Health & social care | 2021 |
| Bell Signature Estates Ltd | Households | 2025 |
| Bell Storage Solutions Ltd | Other services | 2023 |
| Bella Beauty (Swansea) Ltd | Other services | 2023 |
| Bella Bikes Limited | Wholesale & retail | 2012 |
| Bella Ciao (Swansea) Ltd | Hospitality | 2025 |
| Bella Ciao 46 Ltd | Hospitality | 2025 |
| Bella Faith Ltd | Administrative & support | 2021 |
| Bella Hearing Limited | Real estate | 2017 |
| Belle Decor Ltd | Arts & recreation | 2020 |
| Belle’S Bijou Boutique Ltd | Wholesale & retail | 2018 |
| Bellingham Steel and Tinplate Co. Limited | Wholesale & retail | 1992 |
| Bellis & Cursio Properties Ltd | Real estate | 2017 |
| Bello Capelli (Swansea) Limited | Other services | 2013 |
| Bello Capelli Beauty Ltd | Other services | 2017 |
| Bello Jones Properties Ltd | Real estate | 2025 |
| Bellwood Therapies Ltd | Other services | 2018 |
| Belmont Investments Limited | Professional & scientific | 2007 |
| Below High Water Limited | Wholesale & retail | 2012 |
| Belruz Limited | Real estate | 2020 |
| Belvedere Lettings Ltd | Real estate | 2021 |
| Belvedere Wealth Limited | Financial services | 2019 |
| Belvoir Steak and Curry House Limited | Hospitality | 2024 |
| BEN Adams Ltd | Financial services | 2015 |
| BEN Brooker Limited | Construction | 2018 |
| BEN Davies (Construction) Limited | Wholesale & retail | 2003 |
| BEN Evans & SON Limited | Wholesale & retail | 2015 |
| BEN Hughes Engineering Limited | Professional & scientific | 2003 |
| BEN Roderick Property Company Ltd | Real estate | 2021 |
| Bench Marketing Ltd | Professional & scientific | 2021 |
| Bench Travel Limited | Transport & logistics | 2026 |
| Benchmarc Holdings Limited | Financial services | 2025 |
| Benchmarc Investments Limited | Other services | 2025 |
| Benchmarc Logistics Limited | Transport & logistics | 2018 |
| Benchmarc Properties Limited | Real estate | 2025 |
| Benchmark Property Store Limited | Real estate | 2007 |
| Bendix Construction Ltd | Construction | 2019 |
| Bendy Media LLP | | 2009 |
| Bendylegs Limited | Education | 2024 |
| Benjamin Jason Cornelius Limited | Real estate | 2021 |
| Benn Engineering Ltd | Construction | 2019 |
| Benson Watkins & Co Limited | Professional & scientific | 2007 |
| Berfin Aksu Ltd | Education | 2019 |
| Bering Tees Ltd | Manufacturing | 2019 |
| Bernard Hastie (Metspray) Limited | Manufacturing | 1962 |
| Bernard Twomey Consulting Ltd | Administrative & support | 2016 |
| Bernie Davies Global Ltd | Administrative & support | 2020 |
| Berrington Media Ltd | Information & communication | 2012 |
| Berry Housing Ltd | Real estate | 2020 |
| Berry Support Solutions Limited | Administrative & support | 2014 |
| Berties Cafe Ltd | Hospitality | 2020 |
| Berton Management Limited | Wholesale & retail | 2021 |
| Berwyn Minerals Limited | Mining & quarrying | 2010 |
| Berwyn Slate Quarry Limited | Mining & quarrying | 1992 |
| Bespoke Coatings Ltd | Construction | 2021 |
| Bespoke Construction & Plastering Ltd | Construction | 2024 |
| Bespoke Entertainment Group Ltd | Arts & recreation | 2024 |
| Bespoke Hospitality Limited | Hospitality | 2025 |
| Bespoke Kitchen Studios Limited | Wholesale & retail | 2016 |
| Bespoke Living Interiors Limited | Professional & scientific | 2023 |
| Bespoke Living Limited | Professional & scientific | 2023 |
| Bespoke Pension Services Limited | Financial services | 2012 |
| Bespoke Solid Surface Worktops and Counters Limited | Construction | 2015 |
| Best Auto Repairs Port Talbot Ltd | Wholesale & retail | 2019 |
| Best Kept Secret Aesthetics Ltd | Other services | 2020 |
| Best PAW Forward Ltd | Other services | 2009 |
| Bestfoods Mega Mart Swansea Ltd | Wholesale & retail | 2025 |
| Beta Consult Cyfyngedig | Professional & scientific | 2024 |
| Beth-Shalom Properties Limited | Real estate | 2012 |
| Bethal Construction Limited | Construction | 2006 |
| Bethany Lane Management Company Limited | Administrative & support | 2014 |
| Bethel Court Management Co. Limited | Households | 1988 |
| Bethel Properties Ltd | Real estate | 2018 |
| Bethlehem Properties Ltd | Real estate | 2024 |
| Better Bonymaen CIC | Construction | 2025 |
| Better CUT Carpentry (Swansea) Ltd | Construction | 2023 |
| Better Fitness Limited | Arts & recreation | 2025 |
| Better MEN Limited | Health & social care | 2021 |
| Better OFF Edits Ltd | Information & communication | 2020 |
| Betts Automotive Ltd | Wholesale & retail | 2024 |
| BEU IT Ltd | Manufacturing | 2014 |
| Bevan & Buckland Trustees Ltd | Extraterritorial | 2017 |
| Bevan & Buckland Wealth Management Limited | Financial services | 2015 |
| Bevan & Clarke Assets LLP | | 2012 |
| Bevan & Clarke LLP | | 2007 |
| Bevan Buckland Accountants LLP | | 2018 |
| Bevan Buckland Audit Ltd | Professional & scientific | 2025 |
| Bevan Buckland Ltd | Professional & scientific | 2025 |
| Beverley Edwards Training & Consultancy Ltd | Professional & scientific | 2015 |
| BEX Wilby Ltd | Professional & scientific | 2025 |
| Bexmoor Limited | Real estate | 1999 |
| Beynon Holdings Limited | Professional & scientific | 2002 |
| Beynon Homes Ltd | Real estate | 2017 |
| Beyondstock Limited | Information & communication | 2007 |
| Beypazari Mineral Water Ltd | Wholesale & retail | 2020 |
| BFG Media Ltd | Arts & recreation | 2025 |
| Bfra Nwachi Ltd | Transport & logistics | 2021 |
| BFT (GB) Ltd | Financial services | 2007 |