| ANT Nano Ltd | Professional & scientific | 2024 |
| Antiqueclockwise Ltd | Other services | 2012 |
| AP1 Holdings Limited | Real estate | 2023 |
| Apex Agri Systems Ltd | Manufacturing | 2025 |
| Aquabion UK Ltd | Wholesale & retail | 2014 |
| Aqualeak Detection Limited | Manufacturing | 2008 |
| Aragon Infosec Ltd | Information & communication | 2012 |
| ARK A9 GP Limited | Real estate | 2011 |
| ARK A9 L.P. | | 2011 |
| ARK AP1 Limited | Real estate | 2023 |
| ARK Data Centres Limited | Real estate | 2005 |
| ARK Estates 1 Limited | Real estate | 2019 |
| ARK Estates 2 Limited | Real estate | 2019 |
| ARK Estates 3 Limited | Real estate | 2020 |
| ARK Estates 5 Limited | Real estate | 2023 |
| ARK Estates 6 Limited | Real estate | 2025 |
| ARK Estates Cody Park Limited | Real estate | 2013 |
| ARK Estates Development Limited | Construction | 2016 |
| ARK Estates Enfield Limited | Real estate | 2018 |
| ARK Estates Holdings Limited | Real estate | 2013 |
| ARK Estates Spring Park Limited | Real estate | 2016 |
| ARK Europe Holdings Limited | Real estate | 2022 |
| ARK Holdings Spain Limited | Real estate | 2025 |
| ARK LP1 Limited | Real estate | 2025 |
| ARK UP1 Limited | Real estate | 2022 |
| ARK UP2 Limited | Real estate | 2022 |
| ARK UP3 Limited | Real estate | 2022 |
| ARK UP4 Limited | Real estate | 2023 |
| ARK Utilities Limited | Real estate | 2005 |
| Arkevista Ltd | Information & communication | 2009 |
| Arnolds Grove Management Company Limited | Hospitality | 2006 |
| Art Capture Studios Ltd | Professional & scientific | 2026 |
| Artisinat Limited | Wholesale & retail | 2020 |
| Arvensis Ventures Ltd | Professional & scientific | 2021 |
| Arvo Construction Ltd | Construction | 2018 |
| Asbc & Partners (UK) Limited | Administrative & support | 2021 |
| Ashar ALO Limited | Hospitality | 2019 |
| Ashfield Construction Limited | Construction | 2025 |
| ASK LEE Ltd | Hospitality | 2022 |
| Aston Interior Contracts Limited | Wholesale & retail | 1992 |
| ATA Builders Limited | Construction | 2005 |
| Athena Investments Ltd | Real estate | 1994 |
| Athlete Nutrition Limited | Wholesale & retail | 2013 |
| Audiovisual Anti-Piracy Alliance Limited | Other services | 2012 |
| Augusta Investments Limited | Real estate | 2005 |
| Aurora Dental Clinic Corsham Limited | Health & social care | 2020 |
| Autopsia Ltd. | Real estate | 2010 |
| Avisso Limited | Extraterritorial | 2015 |
| Avonglen Holdings Ltd | Real estate | 2019 |
| B&B Health Limited | Other services | 2018 |
| Babyduck Property Services Ltd | Real estate | 2024 |
| Backgardenbliss Ltd | Administrative & support | 2025 |
| Baldwin Stone Carving and Masonry Company Limited | Construction | 1979 |
| Ballard RMS Group Ltd | Financial services | 2025 |
| Bancey Group Limited | Construction | 2017 |
| Barrak Ltd | Financial services | 2023 |
| Barrak, Bhatia & Crean Ltd | Real estate | 2023 |
| Barry Baldwin Sculptor Limited | Arts & recreation | 2021 |
| Bartholomew House Management Company (Corsham) Limited | Households | 1983 |
| Bath Community Kitchen CIC | Hospitality | 2023 |
| Bath Food Tours Ltd | Administrative & support | 2026 |
| Bath Leasehold Management Ltd | Real estate | 2019 |
| Bath Marquees Limited | Administrative & support | 2012 |
| Bath One Ltd | Real estate | 2026 |
| Bath Plastering Limited | Construction | 2017 |
| Bath Stone Fireplaces Ltd | Manufacturing | 2018 |
| Bath Stone Quarry Museum Trust Limited(The) | Arts & recreation | 1984 |
| Bathwick Place Management Company Limited | Households | 2008 |
| Bathwick ST Mary's Limited | Households | 2004 |
| Bay Projects Limited | Professional & scientific | 2022 |
| BB Fixings and Workwear Limited | Wholesale & retail | 2017 |
| Bbounce Limited | Wholesale & retail | 2023 |
| Beazer Electrical Services Limited | Construction | 2003 |
| Beco Private Equity Limited | Professional & scientific | 2011 |
| Bedstone Argyle Management Ltd | Households | 2025 |
| Beech Castle Properties Limited | Real estate | 1952 |
| Beechfield Design Limited | Information & communication | 2012 |
| Beechfield House (Pickwick) Limited | Real estate | 2008 |
| Ben's Kickz & Clothing Ltd | Wholesale & retail | 2025 |
| Berkswell Publishing Company Limited | Information & communication | 1974 |
| Bernie Ross Consulting Ltd | Professional & scientific | 2015 |
| Better Story Ltd | Information & communication | 2019 |
| Betterbank Limited | Real estate | 2002 |
| Bewley Property & Development Ltd | Construction | 2021 |
| Bibliogenics Ltd | Arts & recreation | 2019 |
| Bicon Marketing Limited | Wholesale & retail | 1998 |
| Biobond Ltd | Professional & scientific | 2024 |
| BJ Accounting & Taxation Services Ltd | Professional & scientific | 2023 |
| BJB Consultants Ltd | Professional & scientific | 2006 |
| Black Bear (Holdings) Limited | Financial services | 2011 |
| Bliss (Corsham) Limited | Other services | 2003 |
| BLM Capital Limited | Real estate | 2023 |
| Blue BEE Coffee Ltd | Extraterritorial | 2024 |
| Blue Buddha Limited | Wholesale & retail | 2021 |
| Blue View Properties Limited | Real estate | 2005 |
| Body and Soul Health and Beauty Corsham Limited | Other services | 2014 |
| Bond Builders (Swindon) Limited | Construction | 2026 |
| Bond Electrical Ltd | Construction | 2012 |
| Bondbuilding Limited | Hospitality | 2001 |
| Bourlet Holdings Limited | Financial services | 2024 |