| Anglia Heating & GAS Limited | Construction | 2019 |
| Anglia Renewables Consultancy Ltd | Information & communication | 2025 |
| Anglia Residential Properties Limited | Real estate | 2025 |
| Anglia Rider Training (UK) Ltd | Education | 2014 |
| Anglia Smarttech Limited | Other services | 2015 |
| Anglia Spareline Ltd | Manufacturing | 1993 |
| Anglia Storage Ltd | Administrative & support | 2023 |
| Anglia Taxis Great Yarmouth and Gorleston Limited | Transport & logistics | 2019 |
| Anglia Taxis Great Yarmouth Limited | Transport & logistics | 2018 |
| Anglia Technology Ltd | Extraterritorial | 2022 |
| Anglia Telephones Ltd | Wholesale & retail | 2002 |
| Anglia Tuning Centre Ltd | Wholesale & retail | 2022 |
| Anglian Steel Services Ltd | Construction | 2023 |
| Anglian Sweet and Drink Company Limited | Wholesale & retail | 1996 |
| Anglo Commercial Electrics Limited | Construction | 2020 |
| ANI Dental Clinic Limited | Health & social care | 2007 |
| Ankel Ltd | Real estate | 2025 |
| ANN Nails Spa Ltd | Other services | 2023 |
| Annamalai Medical Services Limited | Health & social care | 2017 |
| Anstey & Woodhouse Limited | Real estate | 2022 |
| Antcliffe Holdings Ltd | Real estate | 2025 |
| ANY Car Tires & Servicing Ltd | Wholesale & retail | 2024 |
| AP Lifting Services Ltd | Mining & quarrying | 2018 |
| APB Decoration Limited | Construction | 2012 |
| APD Builders Limited | Construction | 2019 |
| APD Plant and Groundworks Ltd | Construction | 2021 |
| Apdgroundworks Ltd | Extraterritorial | 2024 |
| Apexverse Ltd | Information & communication | 2025 |
| API Technologies (UK) Limited | Professional & scientific | 2012 |
| Apollonia Properties Ltd | Real estate | 2012 |
| App-Med Limited | Health & social care | 2012 |
| Appa's Kitchen Limited | Hospitality | 2025 |
| Appliance Maintenance Limited | Other services | 2014 |
| Applied Acoustic Engineering Limited | Manufacturing | 1989 |
| Applied Satellite Group Ltd | Information & communication | 2021 |
| Applied Satellite Technology Limited | Information & communication | 1987 |
| Applied Satellite Technology Systems Limited | Information & communication | 1998 |
| Aqsahafsa Limited | Real estate | 2025 |
| Aquazone Group Limited | Financial services | 2023 |
| Aquazone Limited | Construction | 1995 |
| AR Offshore Services Limited | Mining & quarrying | 2018 |
| Arabhi Ltd | Real estate | 2021 |
| ARC Geoservices Limited | Professional & scientific | 2021 |
| Arches Catering Ltd | Hospitality | 2019 |
| Arches Restaurante Ltd | Hospitality | 2026 |
| Archfrank Ltd | Construction | 2025 |
| Archimedean Limited | Transport & logistics | 2016 |
| ARK Offshore International Ltd. | Other services | 1993 |
| Arkgrove Properties Ltd | Administrative & support | 2020 |
| Arkk Scaffolding Limited | Construction | 2024 |
| Armonia Smile Limited | Health & social care | 2024 |
| Armultra Investments Limited | Financial services | 2022 |
| Armultra Limited | Manufacturing | 1985 |
| Aroes Company Limited | Real estate | 2020 |
| Art Beauty and Wellbeing CIC | Education | 2023 |
| Artemor Ltd | Real estate | 2011 |
| Artforgolfers Ltd | Manufacturing | 2024 |
| Artful Communication Ltd | Professional & scientific | 2014 |
| Arthur’S PIE and Mash Ltd | Hospitality | 2023 |
| Artificial Grass Company Norfolk and Suffolk Ltd | Administrative & support | 2021 |
| Artisan Accountant & Co Ltd | Professional & scientific | 2022 |
| Arvas Properties Ltd | Real estate | 2020 |
| Arvor Investments Limited | Extraterritorial | 2013 |
| AS Constructions Essex Ltd | Professional & scientific | 2025 |
| AS Drainage Repairs Ltd | Administrative & support | 2023 |
| ASA Superstores Ltd | Wholesale & retail | 2022 |
| Asams (Holdings) Limited | Financial services | 2011 |
| Asams Limited | Administrative & support | 1988 |
| Ascendant Fiduciaries Ltd | Other services | 2025 |
| Ascending Holdings Ltd | Financial services | 2025 |
| Ascent Helicopters Ltd | Transport & logistics | 2016 |
| Asco Acquisitions Limited | Financial services | 2011 |
| Asco Group Limited | Financial services | 2011 |
| Ashdeane Services Limited | Agriculture & fishing | 2000 |
| Asheervad Ltd | Real estate | 2018 |
| Asheva Ltd | Wholesale & retail | 2023 |
| Ashley De'Ath Ltd | Extraterritorial | 2024 |
| Ashley Nichol & Co Limited | Extraterritorial | 2003 |
| Ashmans Properties Limited | Real estate | 2005 |
| Ashmitha Investment Ltd | Wholesale & retail | 2025 |
| Aslc Services Limited | Professional & scientific | 2026 |
| Aspire to Inspire Nightingale Ltd | Professional & scientific | 2023 |
| Aspp Ltd | Hospitality | 2025 |
| Assetguard Security Ltd | Construction | 2023 |
| Associated Network Services Limited | Construction | 2023 |
| Associated Networks Services Limited | Construction | 2016 |
| Associated Property Solutions Ltd. | Financial services | 2016 |
| Assured Tech Ltd | Information & communication | 2023 |
| AST 5G Ltd | Information & communication | 2019 |
| AST Connections Limited | Information & communication | 2003 |
| AST Marine Sciences Ltd | Information & communication | 2008 |
| AST Oceanics UK Limited | Professional & scientific | 2022 |
| Aston Cross Hospitality Ltd | Hospitality | 2023 |
| Aston Group Limited | Financial services | 2014 |
| Async Software Testing Ltd | Information & communication | 2025 |
| AT Height Solutions (2022) Limited | Administrative & support | 2022 |
| Atadura Limited | Financial services | 2011 |
| ATG Omega Services Ltd | Administrative & support | 2025 |
| Athena Inspection Ltd | Mining & quarrying | 2024 |
| ATI Investments Ltd | Real estate | 2021 |