| Ace Heating & Plumbing Services Ltd | Construction | 2026 |
| Acorn & Co. Property Services Ltd | Households | 2025 |
| Actify Limited | Professional & scientific | 2001 |
| Activate Scientific UK Limited | Wholesale & retail | 2010 |
| Activeplay Education Ltd | Education | 2020 |
| AD Fuels Limited | Administrative & support | 2017 |
| Adamas Industries Limited | Professional & scientific | 1989 |
| Adao Transport Ltd | Transport & logistics | 2020 |
| Adapting Solutions Ltd | Administrative & support | 2023 |
| Addwards Education Solutions Ltd | Education | 2024 |
| Adec (Arts Development in East Cambridgeshire) | Information & communication | 1994 |
| Adelaide Garage Limited | Wholesale & retail | 2019 |
| Adeniyi Okubanjo Limited | Administrative & support | 2019 |
| Adinam Limited | Real estate | 2019 |
| Adinam Services Limited | Construction | 2022 |
| Adprom Limited | Professional & scientific | 2004 |
| Advanced Aircraft Training Limited | Administrative & support | 2006 |
| Advanced Beauty Solutions Limited | Education | 2009 |
| Advanced Pharma Limited | Wholesale & retail | 2010 |
| Advantisec Ltd | Information & communication | 2023 |
| Advent Pathway Ltd | Wholesale & retail | 2026 |
| Adventure Engineering Ltd | Professional & scientific | 2020 |
| Aees Coaching Ltd | Education | 2023 |
| Aetherloom Limited | Information & communication | 2025 |
| Aetosense Ltd | Professional & scientific | 2023 |
| AF Pest Control Ltd | Other services | 2025 |
| AFP Technologies Ltd | Manufacturing | 2020 |
| AG Newco Limited | Financial services | 2016 |
| AGB Logistic Ltd | Transport & logistics | 2026 |
| AGD Carpentry Ltd | Manufacturing | 2025 |
| Agfec Consulting Ltd | Professional & scientific | 2021 |
| Aggrozen Ltd | Information & communication | 2023 |
| Agilas Rise Ltd | Wholesale & retail | 2020 |
| Agresource Limited | Extraterritorial | 2009 |
| Agri Global Ltd | Wholesale & retail | 2011 |
| Agri-Horizon Ltd | Agriculture & fishing | 2023 |
| Agrifac UK Ltd | Wholesale & retail | 1994 |
| Ahash N Co Limited | Wholesale & retail | 2023 |
| Aimpact Consulting Ltd | Professional & scientific | 2025 |
| Airmonkey Ltd | Professional & scientific | 2019 |
| Airsoft Tailoring Ltd | Manufacturing | 2022 |
| Aisg Limited | Professional & scientific | 2004 |
| Aitus Associates Limited | Real estate | 2019 |
| Aitus Commercial Ltd | Real estate | 2017 |
| Aitus Group Holdings Limited | Financial services | 2018 |
| Aitus Investment Ltd | Real estate | 2003 |
| Aitus Residential Ltd | Real estate | 2002 |
| AJ + 2 Limited | Professional & scientific | 2008 |
| AJB & Associates Limited | Wholesale & retail | 2009 |
| AJB & Associates Property Limited | Real estate | 2017 |
| AJC Accounting Ltd | Professional & scientific | 2010 |
| AJG Home Improvements Limited | Construction | 2008 |
| AJN Property Limited | Construction | 2020 |
| AJP Electrical Services Limited | Construction | 2017 |
| AJR Culture Limited | Professional & scientific | 2025 |
| Akeva Safety Solutions Limited | Professional & scientific | 2007 |
| Aktivo Ltd | Wholesale & retail | 2021 |
| AL Razaaq Limited | Health & social care | 2014 |
| Alan Fish Bar Limited | Hospitality | 2019 |
| Alan Freeman Plant Hire Limited | Administrative & support | 2012 |
| Alan Thorne Consulting Services Limited | Professional & scientific | 2026 |
| Alan's Office Services Limited | Transport & logistics | 2021 |
| Alan's Taxis Ltd | Transport & logistics | 2020 |
| Alancalder Ltd | Arts & recreation | 2025 |
| Alderton Homes Limited | Real estate | 2025 |
| Alec Broadhurst Ltd | Professional & scientific | 2025 |
| Alenia Group Ltd | Transport & logistics | 2019 |
| Alexander Recovery Ltd | Wholesale & retail | 2021 |
| Alfelia Limited | Real estate | 2020 |
| Alfresco (ELY) Ltd | Hospitality | 2023 |
| ALICE2024 Nails Ltd | Other services | 2024 |
| Alison Grant Limited | Real estate | 2005 |
| ALL Build Construction Limited | Construction | 2022 |
| ALL Ears ELY Ltd | Public administration | 2023 |
| ALL Things Photography Ltd | Professional & scientific | 2025 |
| ALL Things Wealth Ltd | Financial services | 2020 |
| ALL Timber Construction (Building Contractors) Limited | Construction | 2006 |
| Allgood Building Services Ltd | Construction | 2024 |
| Allgood Property Developments Limited | Construction | 2021 |
| Allinches Ltd. | Arts & recreation | 2020 |
| Allsheds Limited | Manufacturing | 2007 |
| Almost Angels Limited | Other services | 2012 |
| Aloja Limited | Professional & scientific | 2025 |
| Alpine Plumbing Ltd | Extraterritorial | 2018 |
| Alristech Limited | Professional & scientific | 2017 |
| Alter EGO Valeting Ltd | Wholesale & retail | 2017 |
| Altu Living Limited | Wholesale & retail | 2025 |
| Aluminium Scaffold Towers Limited | Construction | 2013 |
| Aluna Home Ltd | Wholesale & retail | 2025 |
| AMA Trans Ltd | Transport & logistics | 2016 |
| Amadeus Consulting and Training Ltd | Education | 2018 |
| Amanda's Concierge Cleaning Limited | Administrative & support | 2012 |
| Ambrose Roofing Limited | Construction | 2021 |
| Ambush Africa Safaris Limited | Administrative & support | 2025 |
| AMD Carpentry Ltd | Construction | 2024 |
| American News Service Limited | Information & communication | 1996 |
| AMG Foods Limited | Wholesale & retail | 2007 |
| AMI Couriers Ltd | Transport & logistics | 2020 |
| Amkeal Holdings Ltd | Real estate | 2020 |
| AML Carpentry & Building Limited | Construction | 2016 |