| Alan Coggins Limited | Real estate | 1971 |
| Alan J Gilby Creative Ltd | Professional & scientific | 2024 |
| Alan Usher Limited | Construction | 2008 |
| Alan W. Simons Limited | Professional & scientific | 2003 |
| Alan Waldock Ltd | Arts & recreation | 2013 |
| Alan Woodard Limited | Wholesale & retail | 2011 |
| Alara Consult Limited | Professional & scientific | 2024 |
| Alawa Group Ltd | Education | 2019 |
| Alba Service & Supply (Camberley) Limited | Other services | 1990 |
| Albany House (Bournemouth) Limited | Households | 1997 |
| Albany Park M.C. Limited | Households | 1989 |
| Albert Road LLP | | 2013 |
| Albin Utilities Ltd | Construction | 2022 |
| Albion Accountants and Business Advisors Ltd | Professional & scientific | 2024 |
| Albion Alloys Group Holdings Limited | Financial services | 2020 |
| Albion Alloys Limited | Wholesale & retail | 1995 |
| Albion Hobbies Limited | Extraterritorial | 2015 |
| Albury & Hall (Dorset) Ltd | Real estate | 2022 |
| Alchemy Encounters Ltd | Hospitality | 2025 |
| Alcyone Management Limited | Real estate | 2009 |
| Alday Limited | Information & communication | 2021 |
| Aldbrickham Limited | Other services | 2020 |
| Aldora Lettings Limited | Real estate | 2013 |
| Aldora Limited | Real estate | 2002 |
| Aldrex Investments Ltd | Real estate | 2022 |
| Aldridge Brownlee Solicitors LLP | | 2008 |
| Aldstein and Company Limited | Professional & scientific | 2016 |
| Alecodan Ltd | Administrative & support | 2025 |
| Aleksandra's Chocolate Café Ltd. | Hospitality | 2018 |
| Alera Consulting Limited | Information & communication | 2005 |
| Alex Care Limited | Administrative & support | 2017 |
| Alex Davison Sports Agency Ltd | Professional & scientific | 2018 |
| Alex Engineering Consulting Ltd | Professional & scientific | 2025 |
| Alex Fast Limited | Transport & logistics | 2017 |
| Alex Rankin Electrical Limited | Construction | 2024 |
| Alexander Court (Richmond Park) Limited | Households | 2000 |
| Alexander Dakers Ltd | Arts & recreation | 2024 |
| Alexander Lodge Management Company Limited | Households | 1993 |
| Alexandra Rodrigues Limited | Financial services | 2019 |
| Alexia Futures Limited | Real estate | 2023 |
| Alfa Beta Limited | Hospitality | 2010 |
| Alfa PM Limited | Real estate | 2017 |
| Alfa RS Limited | Administrative & support | 2015 |
| Alfa Treader Limited | Wholesale & retail | 2026 |
| Alfor Aviation and Technical Services Limited | Professional & scientific | 2023 |
| ALG Holdings Ltd | Financial services | 2018 |
| Alhambra Living Limited | Households | 2023 |
| ALI Bridges Change Management Ltd | Professional & scientific | 2011 |
| Align Mind Body Ltd | Other services | 2020 |
| Alimadad's Taxi Limited | Transport & logistics | 2025 |
| Alimentum Limited | Professional & scientific | 2010 |
| Alinea Design Ltd | Construction | 2021 |
| Aliners Ltd | Health & social care | 2021 |
| Alington Freehold Limited | Households | 2006 |
| Alington House Residents Limited | Households | 1998 |
| Alington Investments Limited | Real estate | 2026 |
| Alinwest Limited | Information & communication | 1995 |
| Alisa Lodge Freehold Limited | Households | 2017 |
| Alisaime Taxi Limited | Transport & logistics | 2024 |
| Alize Media UK Limited | Information & communication | 2023 |
| Aljabban Trading Company Ltd | Wholesale & retail | 2022 |
| Aljbr Ltd | Hospitality | 2018 |
| ALL Build Developments Limited | Construction | 2014 |
| ALL External Cleaning Ltd | Administrative & support | 2015 |
| ALL Groundworks (Southern) Ltd | Construction | 2020 |
| ALL Insured Ltd | Financial services | 2013 |
| ALL Roofing Ltd | Construction | 2015 |
| ALL Solutions Limited | Other services | 2006 |
| ALL Sorts New and Preloved Items Ltd | Wholesale & retail | 2024 |
| ALL Tax Ltd | Professional & scientific | 2018 |
| ALL Wrapped UP (Southbourne) Limited | Wholesale & retail | 2013 |
| All-Clean Waste Management Limited | Water & waste | 2023 |
| All-Gone Pest Control Ltd | Administrative & support | 2024 |
| ALL2PLAY4 Holdings Limited | Financial services | 2025 |
| ALL2PLAY4 Limited | Professional & scientific | 2003 |
| Allamont Ltd | Professional & scientific | 2017 |
| Allan Stewart Limited | Real estate | 2019 |
| Allen Industries Limited | | 1967 |
| Allender Manners Ltd | Information & communication | 2024 |
| Allens Heating Limited | Construction | 2010 |
| Allglaze Dorset Ltd | Construction | 2009 |
| Allgrove Consultancy Limited | Information & communication | 2015 |
| Allgrove Limited | Real estate | 1999 |
| Alliance Groundworks Limited | Construction | 2014 |
| Alliance Scaffolding Services Ltd | Construction | 2023 |
| Allied (Tooling) Ltd | Wholesale & retail | 1983 |
| Allied General Trading Company Ltd | Wholesale & retail | 2020 |
| Allocator Media Ltd | Information & communication | 2025 |
| Allpick Limited | Wholesale & retail | 2025 |
| Allstar Football Limited | Education | 2007 |
| Allyship Development Ltd | Education | 2023 |
| Alma House (Bournemouth) Limited | Households | 2000 |
| Alma Road Freehold Limited | Households | 2007 |
| Almagrove Limited | Wholesale & retail | 1994 |
| Almand Consulting Limited | Extraterritorial | 2001 |
| Almaz Group Limited | Construction | 2019 |
| Almond & Co. (Zero-Waste) Ltd. | Wholesale & retail | 2021 |
| Alnajar Ltd | Wholesale & retail | 2017 |
| Aloft Investments Ltd | Financial services | 2023 |
| ALP Logistics Limited | Wholesale & retail | 2021 |