| Afon Electrical & Renewables Ltd | Extraterritorial | 2024 |
| Afosgroup Limited | Construction | 2015 |
| AFP & JP Associates Ltd | Professional & scientific | 2018 |
| Afrata Capital Limited | Professional & scientific | 2019 |
| Africo Ltd | Hospitality | 2023 |
| AFS Salisbury Limited | Wholesale & retail | 2014 |
| Aggelia Limited | Financial services | 2018 |
| Agha Barber Ltd | Other services | 2025 |
| AGILE101 Limited | Professional & scientific | 2019 |
| AGJ Consultancy Ltd | Professional & scientific | 2014 |
| AGL Building Group Ltd | Real estate | 2019 |
| Agnes and Vera Limited | Wholesale & retail | 2026 |
| Agora Education Ltd | Education | 2026 |
| Agri Consultant Ltd | Agriculture & fishing | 2016 |
| Agristaff Consulting Ltd | Agriculture & fishing | 2013 |
| AGW (Holdings) Ltd | Construction | 2023 |
| AHG Letting Ltd | Real estate | 2025 |
| Ahuvi Limited | Wholesale & retail | 2015 |
| Aidhour Limited | Health & social care | 1998 |
| AIE Precision Ltd | Professional & scientific | 2025 |
| Ainsworth Village Dental Practice Limited | Health & social care | 2013 |
| Air&Port Executive Cars Ltd | Other services | 2018 |
| Airglide Umbrella Services Ltd | Administrative & support | 2023 |
| Airpress Developments Limited | Manufacturing | 2006 |
| AJ Edin Ltd | Real estate | 2023 |
| AJ IT Support Services Ltd | Information & communication | 2018 |
| AJ Security Consulting Ltd | Information & communication | 2014 |
| Ajay Care and Support Ltd | Health & social care | 2021 |
| AJC (Walkford) Ltd | Real estate | 2025 |
| Ajfprogramming Limited | Information & communication | 2013 |
| AJL Associates Ltd | Education | 2022 |
| AK Construction (2026) Limited | Construction | 2026 |
| AK Inventory Properties Ltd | Real estate | 2026 |
| AK Recreations and Leisure Limited | Administrative & support | 2003 |
| AK Shine Salisbury Ltd | Administrative & support | 2026 |
| Akinpeters Consultancy Ltd | Information & communication | 2022 |
| AKM Property Maintenance Ltd | Construction | 2024 |
| Akoda Limited | Wholesale & retail | 2008 |
| Akquis Limited | Extraterritorial | 2010 |
| Akrl Limited | Professional & scientific | 2001 |
| AL Shahania UK Limited | Agriculture & fishing | 2009 |
| Al-Sanad Ltd | Mining & quarrying | 2024 |
| Alabare | Health & social care | 1991 |
| Alamus Ltd | Construction | 2022 |
| Alara Trading Ltd | Wholesale & retail | 2012 |
| Alastair Christie Limited | Information & communication | 2012 |
| Alator Limited | Professional & scientific | 2022 |
| Albahar Consulting Limited | Professional & scientific | 2015 |
| Albany Mews Residents (Barnsbury Park) Limited | Households | 1994 |
| Albion Place Management Limited | Households | 2004 |
| Albion Stonemasons Limited | Construction | 2002 |
| Alchemy Publishing Limited | Information & communication | 2024 |
| Aldbourne Limited | Professional & scientific | 2011 |
| Alder View (Harwell) Management Company Limited | Households | 2016 |
| Alderbury FC Limited | Arts & recreation | 2013 |
| Aldermont Properties Ltd | Real estate | 2024 |
| Aldervale Limited | Administrative & support | 1961 |
| Alderwood Consulting Limited | Administrative & support | 2004 |
| Aldwych Gamewerks Ltd | Wholesale & retail | 2018 |
| Aleant Limited | Professional & scientific | 2026 |
| Alert Training UK Limited | Professional & scientific | 2007 |
| Alex Sandeman Design Ltd | Professional & scientific | 2023 |
| Alex Taylor Limited | Administrative & support | 2014 |
| Alexander Associates (Heritage) Ltd | Administrative & support | 2014 |
| Alexander Associates (Salisbury) Limited | Professional & scientific | 2017 |
| Alexanderplumb Limited | Arts & recreation | 2017 |
| Alexandra Heating Services Limited | Construction | 2007 |
| Alexandra Heating Services Trustee Company Limited | Professional & scientific | 2025 |
| ALF Construction (Southern) Ltd | Construction | 2026 |
| Alfa & Omega MEP Ltd | Extraterritorial | 2024 |
| Alfred's Place Management Limited | Households | 2017 |
| ALI Stewart & Co Limited | Administrative & support | 2013 |
| Alice's in Wonderland Salisbury Ltd | Wholesale & retail | 2015 |
| Alicorn Search Ltd | Administrative & support | 2013 |
| Align-It.Co.Uk 2025 Limited | Information & communication | 2025 |
| Alinea Medical Ltd | Health & social care | 2023 |
| Alinea Surgical Ltd | Health & social care | 2023 |
| Alison Herbert Limited | Professional & scientific | 2005 |
| Alison Herod Consultancy Limited | Professional & scientific | 2025 |
| Alison Weir Tours Limited | Administrative & support | 2010 |
| ALL in Productions Limited | Information & communication | 2012 |
| ALL Media (Print) Ltd | Manufacturing | 2011 |
| ALL the KIT Limited | Administrative & support | 2019 |
| ALL Things Printed Ltd | Administrative & support | 2018 |
| ALL Ways Clean and Care Ltd | Administrative & support | 2021 |
| ALL Your Base Ltd | Information & communication | 2021 |
| Allan Lockyer and SON Limited | Agriculture & fishing | 1960 |
| Allardice Notary Public Ltd | Professional & scientific | 2022 |
| Allen Planning Ltd | Professional & scientific | 2011 |
| Allergy Healthcare Ltd | Administrative & support | 2011 |
| Allerton House Management (Leeds) Limited | Households | 2018 |
| Allgraze Limited | Agriculture & fishing | 2024 |
| Allied GAS Limited | Transport & logistics | 2024 |
| Allium Consulting Ltd | Public administration | 2023 |
| Allnolans Scaffolding Ltd | Construction | 2024 |
| Allow Independent Road-Testing Company Limited | Administrative & support | 2017 |
| Alloy Wheels Direct Ltd | Wholesale & retail | 2004 |
| Alltec Properties Limited | Real estate | 2011 |
| Allthesevens Limited | Transport & logistics | 2015 |
| Alltrust Eput NO 1 Trustees Limited | Professional & scientific | 2025 |