| Advanced Research Works Limited | Information & communication | 2025 |
| Advanced Studies in England Limited | Education | 1987 |
| Advent Visual Ltd | Professional & scientific | 2023 |
| Adventure Alternative Limited | Administrative & support | 2000 |
| Adventure Cafe (Bath) Limited | Hospitality | 2010 |
| Adventure Stories Limited | Professional & scientific | 2018 |
| Advertrader Ltd | Information & communication | 2023 |
| Adzactli Ltd | Information & communication | 2023 |
| AE House Ltd | Hospitality | 2019 |
| AE Residential Limited | Real estate | 2012 |
| Aecia Interiors Limited | Construction | 2013 |
| Aedea Ltd | Professional & scientific | 2023 |
| Aequus Bath Quays Regeneration LLP | | 2025 |
| Aequus Construction Limited | Construction | 2017 |
| Aequus Developments Ltd | Real estate | 2016 |
| Aequus Group Holdings Limited | Financial services | 2022 |
| Aero AG Ltd | Agriculture & fishing | 2026 |
| Aerogel Core Limited | Manufacturing | 2022 |
| Aesthetic Bliss Ltd | Wholesale & retail | 2009 |
| Aeterno Ltd | Professional & scientific | 2020 |
| Aether Photography Ltd | Professional & scientific | 2024 |
| AF Technologies Ltd | Financial services | 2024 |
| Afan Valley Cars Limited | Wholesale & retail | 2017 |
| Affordable Family Law Group Community Interest Company | Administrative & support | 2020 |
| Affuture Financial Limited | Financial services | 2015 |
| Aford Awards Group Holdings Limited | Professional & scientific | 2020 |
| Afpl Limited | Real estate | 2015 |
| Afterthought Software Ltd. | Information & communication | 2011 |
| Against the Grain AP Ltd | Education | 2024 |
| AGE of Steam Limited | Wholesale & retail | 2020 |
| AGE UK (Banes) Trading Ltd | Health & social care | 1998 |
| AGE UK Bath and North East Somerset Limited | Information & communication | 2005 |
| Agile Plus Leadership International Ltd | Professional & scientific | 2019 |
| Agitc Ltd | Wholesale & retail | 2026 |
| Agor Therapeutics Limited | Manufacturing | 2021 |
| Agora AI Ltd | Information & communication | 2025 |
| Agosto ICS Limited | Information & communication | 2016 |
| Agri Engineers Ltd | Manufacturing | 2016 |
| Agribuild Construction Limited | Construction | 2000 |
| AH Presents Limited | Arts & recreation | 2024 |
| AHF Investments Ltd | Real estate | 2023 |
| AI Agent Group Ltd | Professional & scientific | 2024 |
| AI Diagnostics London Limited | Health & social care | 2023 |
| AI Film Studio Ltd | Information & communication | 2026 |
| AI Filmmaker Studio Ltd | Information & communication | 2025 |
| AI Properties London Ltd | Real estate | 2026 |
| Aideen Gowing Design Ltd | Professional & scientific | 2016 |
| Aidi Ltd | Wholesale & retail | 2024 |
| Ainar Tailor Ltd | Manufacturing | 2020 |
| Airley Rook Limited | Professional & scientific | 2023 |
| Airport Transfers Bath Ltd | Transport & logistics | 2025 |
| Airsensa Research Limited | Manufacturing | 2018 |
| Aixtra Limited | Professional & scientific | 2008 |
| AJ & JK Shackell Ltd | Financial services | 2025 |
| AJ Holdings Bath Limited | Financial services | 2021 |
| AJ Online Advertising Ltd | Professional & scientific | 2019 |
| AJ Stephenson Ltd | Professional & scientific | 2022 |
| Aj's Barber Lounge Ltd | Other services | 2021 |
| Ajar Group Limited | Information & communication | 2016 |
| AJB Commercial Properties Limited | Real estate | 2023 |
| AJB Plant Hire Limited | Construction | 2005 |
| AJC Investment Holdings Limited | Financial services | 2022 |
| AJI Mortgages Ltd | Financial services | 2026 |
| AJN Services Limited | Administrative & support | 2018 |
| AJN Solutions Limited | Information & communication | 2014 |
| Ajok 20260 Ltd | Information & communication | 2025 |
| AJS Medical Travels Ltd | Other services | 2026 |
| AJW Property Consultants Limited | Real estate | 2017 |
| Akeman Tours Ltd. | Administrative & support | 2019 |
| Akira Financial Limited | Financial services | 2006 |
| Akira Systems Finance Limited | Financial services | 2024 |
| Akka’S Events Ltd | Administrative & support | 2025 |
| Akkedis Ltd | Professional & scientific | 2019 |
| Akuwata UK Limited | Health & social care | 2024 |
| AL Falafel Takeaway Limited | Hospitality | 2012 |
| AL Impact Consulting Ltd | Professional & scientific | 2026 |
| Al.S.M. Trading Limited | Professional & scientific | 1999 |
| Alabasta Limited | Professional & scientific | 2011 |
| Alamex Limited | Information & communication | 2007 |
| Alan Murdoch Coaching Limited | Education | 2021 |
| Alastair Oxberry Limited | Health & social care | 2019 |
| Alaxiom Ltd | Information & communication | 2011 |
| ALB Associates Limited | Professional & scientific | 2007 |
| ALB Energy Surveys Limited | Professional & scientific | 2010 |
| Albany Communication Trust Limited | Public administration | 2007 |
| Albany Court (Bath) Management Company Limited | Households | 2003 |
| Albany Guest House (Bath) Limited | Hospitality | 2006 |
| Albany House (Scilly) Management Company Ltd | Households | 2022 |
| Albarino Ltd | Professional & scientific | 2019 |
| Alcoholery Ltd | Manufacturing | 2023 |
| Aldenvere Ltd | Professional & scientific | 2026 |
| Aldridges of Bath Limited | Administrative & support | 1987 |
| Alejandra Restaurant Group Limited | Hospitality | 2023 |
| Aleph Investment II Ltd | Financial services | 2018 |
| Aleph Investment Ltd | Financial services | 2013 |
| Aleph Property Investment Ltd | Real estate | 2016 |
| Alessandra UK Limited | Hospitality | 2011 |
| Alex Cowey Ltd | Health & social care | 2012 |
| Alex Griffiths Photography Ltd | Professional & scientific | 2017 |
| Alex Nail Publishing Ltd | Information & communication | 2023 |