| Amae Cara International Ltd | Information & communication | 2025 |
| Amalfi Luxury Design Ltd | Professional & scientific | 2021 |
| Amalfi Wellness Ltd | Construction | 2021 |
| Ambercraft Couriers Ltd | Transport & logistics | 2026 |
| Ambler & Co Ltd. | Extraterritorial | 2014 |
| Ambler Accountants Limited | Other services | 2008 |
| AMI Leisure Limited | Professional & scientific | 2004 |
| Amiri Productions Limited | Information & communication | 2024 |
| Amiscam Ltd | Construction | 2026 |
| Amit Enterprise Ltd | Real estate | 2018 |
| AML HGV Services Ltd | Wholesale & retail | 2016 |
| Amour Properties Ltd. | Administrative & support | 2016 |
| AMY Wentworth-Edwards Ltd | Health & social care | 2014 |
| Andrew S Campbell Associates Limited | Administrative & support | 2008 |
| Andy Lewis Carpentry Limited | Construction | 2017 |
| Angelplay Limited | Professional & scientific | 2014 |
| Anglia CNC Engineering Ltd | Manufacturing | 1973 |
| Animal Country Club Limited | Other services | 2017 |
| Anned Developments Ltd | Construction | 2022 |
| Anned Scaffolding Ltd | Construction | 2024 |
| Ansells Developments Ltd | Real estate | 2014 |
| Antrobus Trading Limited | Real estate | 2016 |
| Anujai Group Ltd | Health & social care | 2018 |
| Aoife Scaffolding Ltd | Construction | 2025 |
| Apdp Developments Ltd | Construction | 2016 |
| APE Productions Limited | Arts & recreation | 2005 |
| Apex Auto House Ltd | Wholesale & retail | 2026 |
| Apex Demolition Limited | Construction | 2012 |
| Apex Plant Hire (Peterborough) Limited | Administrative & support | 2015 |
| Apps Contracting Limited | Construction | 2020 |
| Apps Group Limited | Financial services | 2023 |
| Aqeel Estates Ltd | Real estate | 2024 |
| Aqua Advanced Skincare Limited | Wholesale & retail | 2013 |
| Aquarius (ST Ives) Ltd | Construction | 2014 |
| Aravind Property Limited | Real estate | 2022 |
| Arboreal Marketing Ltd | Professional & scientific | 2023 |
| Arena Event Services Group Limited | Arts & recreation | 2000 |
| Arena Events Group Limited | Arts & recreation | 2017 |
| Argo Sentinel Ltd | Administrative & support | 2025 |
| Arif & Co Ltd | Professional & scientific | 2013 |
| Armadale Court Management Company Limited | Real estate | 2015 |
| Armco Barrier Supplies Ltd | Manufacturing | 2016 |
| Armour Plated Limited | Information & communication | 2005 |
| Arndit Ltd. | Information & communication | 2016 |
| Arne Carpentry Ltd | Construction | 2023 |
| Artful Accountancy Ltd | Professional & scientific | 2024 |
| Artlantic Limited | Arts & recreation | 2004 |
| AS ST Ives Limited | Hospitality | 2020 |
| Ascent IT Ltd | Information & communication | 2013 |
| Ascot Car Rentals Ltd | Administrative & support | 2023 |
| Ascot Finance (U.K.) Holdings Limited | Financial services | 2022 |
| ASH Minda Catering Ltd | Hospitality | 2025 |
| Ashburn Accountancy Limited | Professional & scientific | 2015 |
| Ashcroft Electrical Ltd | Construction | 2024 |
| Ashley Grey Executive Search Limited | Administrative & support | 2016 |
| Ashton Electrical Energy Ltd | Construction | 2021 |
| Ashton Property Development Limited | Construction | 2021 |
| Aspen Building Limited | Construction | 2018 |
| Aspire UK Investments Ltd | Real estate | 2007 |
| Association of Conference Executives Limited | Other services | 1971 |
| Ataman Brothers Limited | Hospitality | 2024 |
| Atlantic Studio EOT Limited | Professional & scientific | 2019 |
| Attenbroke Ltd | Information & communication | 2020 |
| Auriga Project Management Limited | Professional & scientific | 1999 |
| Austen Property Consultants Ltd | Real estate | 2024 |
| Autair Management Services Limited | Real estate | 1970 |
| Auto Data Guru Ltd | Information & communication | 2014 |
| Autospa (Peterborough) Ltd | Administrative & support | 2017 |
| Autostore Logistics Ltd | Administrative & support | 2024 |
| AV8 Distribution Limited | Wholesale & retail | 2026 |
| Avalon Aesthetic Ltd | Health & social care | 2018 |
| Avant Collective Limited | Real estate | 2025 |
| Avora Events Ltd | Professional & scientific | 2025 |
| AYR Holiday Properties Limited | Construction | 2008 |
| AYR Property Management Ltd | Real estate | 2024 |
| Ayvi Ltd | Wholesale & retail | 2022 |
| Azura Blue Consulting Limited | Professional & scientific | 2025 |
| Azure (Caterham) Limited | Real estate | 2016 |
| B Falkner Ltd | Wholesale & retail | 2023 |
| B J Stimson Property Solutions Limited | Construction | 2013 |
| B-Buddy Ltd | Information & communication | 2026 |
| Back Road Artworks Ltd | Other services | 2018 |
| Badgers Food Forest CIC | Agriculture & fishing | 2023 |
| Bakehouse Design Limited | Professional & scientific | 2024 |
| Bakehouse Manufacturing Limited | Manufacturing | 2024 |
| Bakewell Property Management Limited | Households | 2018 |
| Banksys Burgers Ltd | Hospitality | 2026 |
| Banquet Inn Limited | Wholesale & retail | 2013 |
| Bantham Radar Limited | Information & communication | 2021 |
| BAO Agency Limited | Information & communication | 2012 |
| Barak Holdings Limited | Financial services | 2025 |
| Barak Investments Limited | Administrative & support | 2025 |
| Barnoon Carpentry and Build Limited | Construction | 2025 |
| Barnoon Property Group Limited | Construction | 2025 |
| Barretow Ltd | Information & communication | 2019 |
| Barrington Broadcasting Limited | Extraterritorial | 2022 |
| Barwell Global Limited | Manufacturing | 2008 |
| Barwell Rubber Company Limited | Professional & scientific | 1992 |
| Batemans Transport & Taxi Ltd | Transport & logistics | 2019 |
| Baule Limited | Real estate | 2015 |