| ADI Treatments (Holdings) Limited | Manufacturing | 1999 |
| ADM (Midlands) Ltd | Wholesale & retail | 2022 |
| Adraburgh Limited | Manufacturing | 1978 |
| Advanced Circuit Engineering Limited | Administrative & support | 1996 |
| Advanced Management Facilities Limited | Real estate | 2005 |
| Advanced Process Solutions Limited | Professional & scientific | 2007 |
| Advanta Consulting Limited | Professional & scientific | 2001 |
| Adwin Spring Company Limited | Manufacturing | 1958 |
| Aerospacedirect Limited | Administrative & support | 2001 |
| Aethelwulf Investments Ltd | Households | 2023 |
| Affina Trading Ltd | Wholesale & retail | 2020 |
| African Caribbean Community Initiative (A.C.C.I.) | Health & social care | 2000 |
| AG Servicing Limited | Manufacturing | 2004 |
| Ageless Beauty Group Limited | Manufacturing | 2023 |
| Agetion Limited | | 1975 |
| Agoraxis Global Limited | Wholesale & retail | 2026 |
| AHK Investments Limited | Real estate | 2002 |
| Ahmad Constructions Limited | Construction | 2004 |
| Aimidi Ltd | Manufacturing | 2023 |
| Aircon Midlands Limited | Extraterritorial | 2004 |
| Airdora Limited | Real estate | 2000 |
| Airneed (U.K.) Limited | Wholesale & retail | 1994 |
| Airocall Limited | | 1987 |
| Aivlom Creative Ltd | Professional & scientific | 2006 |
| AJ Hampton Properties Ltd | Administrative & support | 2018 |
| AJF Technical Services Limited | Manufacturing | 2014 |
| AJS (Coventry) Limited | Real estate | 2005 |
| AJT Property Services Limited | Construction | 2003 |
| Akber & Company Limited | Professional & scientific | 2006 |
| AKC Business Solutions Limited | Information & communication | 2007 |
| Akem Limited | Hospitality | 2005 |
| Akeras Medical Ltd | Health & social care | 2024 |
| Akron Holdings Limited | Financial services | 2024 |
| Akshay Convenience Store Ltd | Wholesale & retail | 2022 |
| Aktiva UND Passiva Limited | Administrative & support | 2004 |
| AL Group China Ltd | Wholesale & retail | 2024 |
| AL Shifa Trust Ltd | Professional & scientific | 1998 |
| Al-Ikhlas Foundation | Education | 2010 |
| Alan Warwick Limited | Wholesale & retail | 1996 |
| Alan Webb Limited | Construction | 2005 |
| Albion Haulage Ltd | Transport & logistics | 2025 |
| Albion Sections Limited | Manufacturing | 1992 |
| Albrighton Roofing Limited | Construction | 2007 |
| Alexander Stevens (1995) Limited | Real estate | 1990 |
| Alexandra Bookkeeping + Accountancy Services Limited | Professional & scientific | 2003 |
| Allen's (Stourbridge) Transport Limited | Transport & logistics | 1989 |
| Allform Precision Limited | Manufacturing | 2000 |
| Allforms of Print (UK) Limited | Manufacturing | 2005 |
| Alliance Joinery Limited | Manufacturing | 2005 |
| Allstar Developments Limited | Construction | 1970 |
| Altec (Analytical & Technical) Services Ltd | Professional & scientific | 2008 |
| Altus Homes Limited | Real estate | 1966 |
| Alucard Publishing Limited | Manufacturing | 1975 |
| Alucast Limited | Manufacturing | 2003 |
| Alvin Care Services UK Limited | Health & social care | 2009 |
| Always a Winner Ltd | Wholesale & retail | 2018 |
| Alwin Limited | Water & waste | 1994 |
| Amanda Louise Limited | Wholesale & retail | 1998 |
| Amber X Technology Limited | Wholesale & retail | 2023 |
| Ambrosia Property Ltd | Real estate | 2002 |
| Amglobbal Ltd | Wholesale & retail | 2025 |
| Ampteam Assets Limited | Construction | 2006 |
| ANA Mini Market Ltd | Wholesale & retail | 2025 |
| Andrew Lane Consulting Limited | Information & communication | 2006 |
| Andrews Coatings Limited | Wholesale & retail | 2001 |
| ANF Interiors Ltd. | Construction | 2025 |
| Angel Feet Podiatry Limited | Health & social care | 2008 |
| Anglo Asian Marketing Limited | Professional & scientific | 2005 |
| Anglo-Brasilian Consulting Limited | Professional & scientific | 1997 |
| Anjuman Limited | Health & social care | 2000 |
| Ant's Jewellery Repairs & Sales Ltd | Other services | 2007 |
| Antartiques Investments Limited | Real estate | 2004 |
| Anthony Collins Limited | Professional & scientific | 1990 |
| Anthony Collins Solicitors LLP | | 2005 |
| Anthony Michael Hair Design Limited | Other services | 2000 |
| Anthony Whittaker Building and Civil Engineering Contractors Limited | Construction | 2000 |
| Antill Saddlery Limited | | 1981 |
| Antilocapra Solutions Ltd | Manufacturing | 2023 |
| Anto Internet Technology Co., Ltd | Wholesale & retail | 2023 |
| Apex Machining Services Limited | Manufacturing | 1996 |
| Apex Outdoor Advertising Limited | Professional & scientific | 1997 |
| Apex Prime Consultants Ltd | Construction | 2025 |
| Aplusv Group Holdings Limited | Extraterritorial | 2014 |
| Apollo Accessories Limited | Wholesale & retail | 1988 |
| Apollo Electrical Contractors Ltd | Construction | 2007 |
| Apollo Flow Measurement Limited | Manufacturing | 1993 |
| Appleby Mall Limited | Professional & scientific | 2003 |
| Aprex Limited | Health & social care | 2005 |
| Apropos Consultancy Limited | Information & communication | 2012 |
| APT Services Limited | Professional & scientific | 1991 |
| Aqua Coatings Limited | Manufacturing | 1995 |
| Aqua Display Limited | | 1987 |
| Aquabond (UK) Limited | | 1993 |
| Aquadove Limited | Transport & logistics | 2004 |
| Aquawhite Estate Holdings Limited | Transport & logistics | 2023 |
| Arbor Townscape (Contracts) Limited | Construction | 1973 |
| Arbor Townscape Limited | Construction | 1971 |
| Arcadia Freight Services Limited | Transport & logistics | 2005 |
| Archer, Bassett & Co Limited | Real estate | 1998 |
| Arden Metals Limited | Wholesale & retail | 2000 |