| Alan Lawton Engineering Consultancy Limited | Administrative & support | 2005 |
| Alan Smith Garages Limited | Wholesale & retail | 2002 |
| Alan Stuart Investments Limited | Administrative & support | 2011 |
| Alan Tang Ltd | Professional & scientific | 2023 |
| Alan Young Limited | Construction | 2008 |
| Aland Cars Ltd | Wholesale & retail | 2023 |
| Alasdair Mclay Consulting Limited | Professional & scientific | 2016 |
| Alasia Intelligence Ltd | Information & communication | 2025 |
| Alastair Rose Limited | Financial services | 2025 |
| Albany Consultancy Limited | Professional & scientific | 2021 |
| Albatross BUS & Coaches Ltd | Transport & logistics | 2023 |
| Albatross Cars Derby Ltd | Transport & logistics | 2017 |
| Albert Ball Property Ltd | Real estate | 2024 |
| Albert Colledge and SON Limited | Wholesale & retail | 1964 |
| Albie (Midlands) Ltd | Real estate | 2023 |
| Albion Fortress Bidco Limited | Financial services | 2025 |
| Alchemy Analytica Ltd | Professional & scientific | 2021 |
| Alchemy Bloodstock Ltd | Agriculture & fishing | 2020 |
| Alchemy of the Imagination Ltd | Professional & scientific | 2020 |
| Alchemy Oils Ltd | Manufacturing | 2013 |
| ALD Couriers Ltd | Transport & logistics | 2025 |
| Alderson Property Ltd | Real estate | 2025 |
| Aldwell Freeholds Ltd | Real estate | 2023 |
| Aleah J Hair Limited | Other services | 2025 |
| Alednak Limited | Manufacturing | 2016 |
| Alef Partners Limited | Real estate | 2022 |
| Alek HGV Ltd | Transport & logistics | 2023 |
| Aleks a Transport Ltd | Transport & logistics | 2017 |
| Aleks AIP Limited | Construction | 2020 |
| Alen Retail Ltd | Wholesale & retail | 2024 |
| Alephbet Ltd | Construction | 2020 |
| Alerter Group Limited | Manufacturing | 2000 |
| Alex & Alma Property Ltd | Real estate | 2025 |
| Alex Christian Limited | Professional & scientific | 2006 |
| Alex Laundry Services Ltd | Wholesale & retail | 2023 |
| Alexander & Co Solicitors LLP | | 2013 |
| Alexander David Limited | Professional & scientific | 2022 |
| Alexander Gardens Management Company Limited | Households | 2021 |
| Alexander Grey Ltd | Construction | 2023 |
| Alexander J Shaw Ltd | Arts & recreation | 2021 |
| Alexander James Hodgkinson Contracting Limited | Construction | 2019 |
| Alexander Removals Ltd | Transport & logistics | 2022 |
| Alexandros Zeimpekis Ltd | Health & social care | 2025 |
| Alexd Consulting Ltd | Professional & scientific | 2014 |
| Alexious Limited | Professional & scientific | 2024 |
| Alexius Power Engineering Limited | Manufacturing | 2025 |
| Alexlever Ltd | Administrative & support | 2017 |
| Alfa Funding Limited | Wholesale & retail | 2011 |
| Alfa Physio Limited | Health & social care | 2017 |
| Alfa Property Legacy Ltd | Real estate | 2025 |
| Alfie Salad Limited | Wholesale & retail | 2012 |
| Alfisags Radiology Ltd | Health & social care | 2024 |
| Alfred Developments Ltd | Construction | 2022 |
| Alfred Mcalpine Slate Penrhyn Limited | Extraterritorial | 1951 |
| Alfredo Holdings Limited | Real estate | 2024 |
| Alfreton Road Stores Ltd | Wholesale & retail | 2025 |
| Alfreton Town Football Club Limited | Arts & recreation | 1986 |
| Algae Services Ltd | Administrative & support | 2026 |
| Alhoma Limited | Administrative & support | 2010 |
| ALI CUT Ltd | Other services | 2024 |
| ALI Hamza Goods Ltd | Wholesale & retail | 2025 |
| ALI HAQ Ltd | Transport & logistics | 2025 |
| Ali's Travel Derby Ltd | Administrative & support | 2023 |
| Alicia Transport Logistics Ltd | Transport & logistics | 2023 |
| Alicom Ltd | Other services | 2016 |
| Aligned Support Services Ltd | Administrative & support | 2023 |
| Alin POP Contractors Ltd | Construction | 2019 |
| Alinea Homes Limited | Real estate | 2018 |
| Alinea Investments Limited | Real estate | 2018 |
| Alisah Foods Ltd | Hospitality | 2023 |
| Alise Secure Validation Ltd | Other services | 2024 |
| Alismitch Global Services (UK) Ltd | Education | 2024 |
| Alison Lightfoot Ltd | Manufacturing | 2025 |
| Alixir Ltd | Professional & scientific | 2012 |
| Ali’S Auto Care Ltd | Wholesale & retail | 2025 |
| Aljnzoma Ltd | Transport & logistics | 2024 |
| Alka IT Services Limited | Information & communication | 2000 |
| Alkadine Limited | Administrative & support | 2023 |
| Alkhemy Group Ltd | Professional & scientific | 2021 |
| ALL About Nails Limited | Other services | 2025 |
| ALL About YOU Mobile Therapies Ltd | Health & social care | 2019 |
| ALL Air Cooling Air Conditioning Limited | Construction | 2020 |
| ALL Assist Limited | Professional & scientific | 2017 |
| ALL Build Developments 65 Ltd | Construction | 2026 |
| ALL County Kannada Association UK C.I.C. | Education | 2021 |
| ALL for Good Limited | Professional & scientific | 2005 |
| ALL Renewables Limited | Construction | 2012 |
| ALL Round Property Solutions Limited | Administrative & support | 2011 |
| ALL Seasons Gardening Services (Midlands) Limited | Administrative & support | 2020 |
| ALL Seasons Gardening/Landscapes Ltd | Professional & scientific | 2024 |
| ALL Star Diamonds Ltd | Real estate | 2024 |
| ALL the Way Coaching Limited | Administrative & support | 2024 |
| ALL Together Services Limited | Education | 2021 |
| Allan Henderson Building Surveyor Limited | Professional & scientific | 2023 |
| Allazo Consulting Services Ltd | Professional & scientific | 2017 |
| Allen's DRY Cleaners Limited | Other services | 2000 |
| Allentan Sunbeds Ltd | Other services | 2022 |
| Allenton Appliances Limited | Wholesale & retail | 2009 |
| Allenton Balti House Ltd | Hospitality | 2025 |
| Allenton Balti Limited | Hospitality | 2019 |