| Beech Tree Training Limited | Education | 2010 |
| Beechwood Fitness Limited | Arts & recreation | 2025 |
| Beecourt Limited | Extraterritorial | 2017 |
| Beefy's Skips Ltd | Water & waste | 2012 |
| Beejoy Limited | Real estate | 2025 |
| Beer Marine Ltd | Manufacturing | 2024 |
| Bees Keys Swindon Limited | Education | 2024 |
| Beesleys Tools Ltd | Wholesale & retail | 2022 |
| Befitting Supportive Care Limited | Public administration | 2023 |
| Begley E Bikes Ltd | Manufacturing | 2025 |
| BEL Ombre Properties Limited | Real estate | 2013 |
| Bela Flor Ltd | Other services | 2017 |
| Belevie Ltd | Education | 2022 |
| Believe Interior Solution Ltd | Construction | 2022 |
| Bella Atmosfera Ltd | Hospitality | 2022 |
| Bellajojos Spa Ltd | Other services | 2018 |
| Bellamy Group Limited | Construction | 2018 |
| Bellcourt Management Limited | Real estate | 2000 |
| Belle Masion Limited | Hospitality | 2023 |
| Bellring Limited | Real estate | 2021 |
| Bellroc Ltd | Hospitality | 2023 |
| Belmont Management Company Limited | Households | 2003 |
| Beloit Ltd | Manufacturing | 2020 |
| Bema 1983 Heat Pumps Limited | Construction | 2026 |
| Bemo GSR International Ltd | Construction | 2025 |
| BEN Hicks Property Group Ltd | Real estate | 2022 |
| BEN Lambert Agricultural Contractors Limited | Agriculture & fishing | 2011 |
| BEN Moody Builders Limited | Construction | 2014 |
| BEN Wolf Ltd | Transport & logistics | 2025 |
| Benchfield Plastic Surgery Limited | Health & social care | 2018 |
| Benchmark Designs Limited | Construction | 2008 |
| Bendene Consultants Limited | Information & communication | 2000 |
| Bene Residential Limited | Real estate | 2025 |
| Benerdz Ltd | Wholesale & retail | 2024 |
| Benfields Executive Travel Ltd | Transport & logistics | 2018 |
| Benic Ltd | Professional & scientific | 2021 |
| Beniwal Truckline Limited | Transport & logistics | 2026 |
| Benn Airey Consultants Ltd | Information & communication | 2014 |
| Benn Consulting Ltd | Information & communication | 2023 |
| Bennett & Sons Plumbing Limited | Construction | 2025 |
| Bennett Capital Limited | Financial services | 2025 |
| Bennett Capital Property Limited | Real estate | 2025 |
| Bentleyblack Ltd | Transport & logistics | 2025 |
| Benvolio Leisure Limited | Hospitality | 2013 |
| Benz Health Consultancy Limited | Health & social care | 2025 |
| Beowolf Capital Limited | Financial services | 2019 |
| Beread Ltd | Administrative & support | 2024 |
| Berkeley Wealth Audit Services Limited | Professional & scientific | 2024 |
| Berkshire Caravans Limited | Extraterritorial | 2003 |
| Berkshire Systemic Solutions Limited | Professional & scientific | 2009 |
| Bernard Geomatics Limited | Professional & scientific | 2013 |
| Bernards (Swindon) | Professional & scientific | 1962 |
| Berny Express Ltd | Transport & logistics | 2016 |
| Berry Nest Limited | Wholesale & retail | 2025 |
| Berry's Roofing Limited | Construction | 2021 |
| Bert's Books Ltd | Wholesale & retail | 2024 |
| Bescotti Ltd | Extraterritorial | 2021 |
| Bespoke Alliance Ltd | Information & communication | 2026 |
| Bespoke Cotswold Limited | Wholesale & retail | 2025 |
| Bespoke Guardians Ltd | Health & social care | 2019 |
| Bespoke Installations Limited | Construction | 2001 |
| Bespoke Precision Engineering Ltd | Manufacturing | 2024 |
| Bespokebp Ltd | Administrative & support | 2023 |
| Best - BE a Better YOU | Health & social care | 2020 |
| Best Bar None Limited | Hospitality | 2013 |
| Best BBQ Ltd | Hospitality | 2023 |
| Best Care Professionals Ltd | Administrative & support | 2022 |
| Best Choice Healthcare Limited | Administrative & support | 2026 |
| Best Kebab & Breakfast Limited | Hospitality | 2026 |
| Best Mates - Wegotya Limited | Other services | 2023 |
| Best Mind Therapy Limited | Health & social care | 2022 |
| Best of Health (Wootton Bassett) Limited | Health & social care | 2001 |
| Best Pinnacle Care Limited | Health & social care | 2020 |
| Best Scientific Limited | Professional & scientific | 2026 |
| Best Test Pizza Ltd | Hospitality | 2026 |
| Best Way Healthcare Ltd | Health & social care | 2024 |
| Best YOU Beauty & Wellbeing Limited | Other services | 2020 |
| Best YOU Products Limited | Other services | 2020 |
| Best YOU Training Limited | Other services | 2020 |
| BESTCLEANERS4U Ltd | Administrative & support | 2010 |
| Besthomes Construction Limited | Construction | 2002 |
| Beta Chow Limited | Hospitality | 2024 |
| Bethany Youth Services Limited | Health & social care | 2026 |
| Bethesna Limited | Hospitality | 2023 |
| BETHMAK247 Care Limited | Public administration | 2024 |
| Betr Tutors Ltd | Education | 2025 |
| Better Bargains Swindon Ltd | Wholesale & retail | 2020 |
| Better Call Paul Garden and Maintenance Ltd | Administrative & support | 2023 |
| Betterhandy Limited | Wholesale & retail | 1992 |
| Betty Blossom Limited | Construction | 2020 |
| Betula Ltd | Administrative & support | 2010 |
| Beulah Consults Limited | Wholesale & retail | 2016 |
| Bevan Transport Limited | Transport & logistics | 2001 |
| Bevington Express Limited | Transport & logistics | 2021 |
| Bevirs Limited | Extraterritorial | 1988 |
| Beyond the Care UK Ltd | Health & social care | 2022 |
| Bezaleel Educate Limited | Education | 2025 |
| Bezaleel Investment Limited | Real estate | 2025 |
| Bezian Limited | Professional & scientific | 2023 |
| BF Rentals Ltd | Real estate | 2018 |