| Animal Madness Ltd | Education | 2018 |
| Animal Trust Property Limited | Real estate | 2012 |
| Animal Trust Vets C.I.C. | Professional & scientific | 2012 |
| Anmhai Limited | Health & social care | 2026 |
| Anna Potticary Health & Fitness Ltd | Health & social care | 2024 |
| Anna's Simply Cakes Limited | Manufacturing | 2021 |
| Annapurna Eats UK Ltd | Hospitality | 2024 |
| Ansonette Ltd | Health & social care | 2024 |
| Anzio Heating and Plumbing Ltd | Construction | 2026 |
| AO Capital Investments Ltd | Financial services | 2025 |
| AP Friends Ltd | Wholesale & retail | 2023 |
| AP Site Solutions Ltd | Construction | 2021 |
| APB Motor Services Ltd | Wholesale & retail | 2016 |
| Apep Limited | Professional & scientific | 2014 |
| Apex Alignment Ltd | Administrative & support | 2020 |
| Apex Collectibles Ltd | Wholesale & retail | 2026 |
| Apex Developments 246 Limited | Real estate | 2020 |
| Apex Electrical Install Ltd | Construction | 2026 |
| Apex Flooring Solutions Ltd | Construction | 2017 |
| Apex Hereford Holdco Limited | Health & social care | 2026 |
| Apex Lifestyle Group Limited | Administrative & support | 2025 |
| Apex Pro Limited | Construction | 2025 |
| Apex Vending Ltd | Hospitality | 2024 |
| Apis MC Limited | Manufacturing | 2016 |
| Apura Limited | Wholesale & retail | 2024 |
| APY Dental Ltd | Health & social care | 2026 |
| AR Nuttall Ltd | Education | 2023 |
| Arch Capstone Ltd | Construction | 2025 |
| Archer Aqua Limited | Administrative & support | 2016 |
| Archer Plant Limited | Administrative & support | 2025 |
| Arcot Dental Limited | Health & social care | 2022 |
| ARG Health Care Ltd | Health & social care | 2021 |
| ARG Homes Limited | Households | 2019 |
| ARI Bardo Limited | Health & social care | 2024 |
| Ari&Ian Ltd | Transport & logistics | 2026 |
| ARK Coachline Limited | Transport & logistics | 2001 |
| Armymaq Limited | Health & social care | 2018 |
| Arno Surgery Limited | Health & social care | 2013 |
| ARP Distribution and Delivery Ltd | Transport & logistics | 2019 |
| ARR Care Recruitment Ltd | Hospitality | 2025 |
| Artisan Bindery Ltd | Arts & recreation | 2019 |
| AS Medical & Healthcare Ltd | Health & social care | 2026 |
| ASA Surgical Limited | Health & social care | 2014 |
| Asap Comply Limited | Professional & scientific | 2012 |
| ASC Alpha Limited | Financial services | 2026 |
| Ascot Mobile Installations Limited | Information & communication | 2004 |
| Ashby Road Ltd | Health & social care | 2006 |
| Ashcroft Maintenance Services Ltd | Other services | 2019 |
| Ashley & Bailey Developments Limited | Real estate | 2025 |
| Ashley & Bailey Ltd | Real estate | 2023 |
| Ashley & Lewis Holdings Limited | Financial services | 2023 |
| Ashley & Lewis Paints Limited | Other services | 2001 |
| Ashley & Lewis Property Developments Limited | Real estate | 2022 |
| Ashley & Lewis Property Investments Limited | Real estate | 2018 |
| Ashley & Lewis Short Term Rentals Limited | Real estate | 2023 |
| ASK Electrical (Little Sutton) Limited | Construction | 2010 |
| Asortiz Ltd | Information & communication | 2025 |
| Aspedan Ltd | Professional & scientific | 2022 |
| Aspire Property Partnership Limited | Construction | 2017 |
| Aspiring Lives Ltd | Health & social care | 2018 |
| Aspiring Living Limited | Real estate | 2026 |
| Asset Integrity Solutions Limited | Manufacturing | 2007 |
| Associated Industries Limited | Wholesale & retail | 1984 |
| Associated Petro Engineering Limited | | 1970 |
| Association of Independent Museums | Arts & recreation | 1978 |
| Astbury Park (Congleton) Management Company Limited | Real estate | 2022 |
| Aston Risk Management Limited | Financial services | 2012 |
| Astra Property Care Limited | Construction | 2009 |
| Astralite Communications Ltd | Information & communication | 2014 |
| Athena Developments (Cheshire) Limited | Real estate | 2015 |
| Athlete LAB UK Ltd | Arts & recreation | 2024 |
| Atulate Engineering Ltd | Professional & scientific | 2026 |
| ATZ Home Improvements Ltd | Construction | 2024 |
| AUR Dental Limited | Health & social care | 2025 |
| Aurora Imaging Limited | Information & communication | 2000 |
| Austin Marketing Limited | Professional & scientific | 2026 |
| Authenticraft Limited | Information & communication | 2025 |
| Autofix Direct Limited | Wholesale & retail | 2015 |
| Automotive Component Remanufacturing Limited | Manufacturing | 1995 |
| Aviary Farm Ltd | Agriculture & fishing | 2025 |
| Aviate Management Limited | Other services | 2008 |
| Aviate TIG Co Ltd | Financial services | 2023 |
| Avista Financial Planning Ltd | Financial services | 2013 |
| AVS Steps Limited | Wholesale & retail | 2000 |
| AW Coaching in the Community CIC | Education | 2024 |
| AW Dental Arts Limited | Health & social care | 2022 |
| Awhyte Consulting Ltd | Professional & scientific | 2013 |
| AWP Precision Ltd | Manufacturing | 2011 |
| AWS Fibre Ltd | Manufacturing | 2018 |
| Axcroft Limited | Hospitality | 2010 |
| Axelytics Ltd | Information & communication | 2017 |
| AXM Productions Ltd | Information & communication | 2022 |
| Azaen Ltd | Financial services | 2025 |
| B-Assured Health & Safety Limited | Health & social care | 2021 |
| B.N.K Brickwork Ltd | Construction | 2025 |
| B20 Services Ltd | Construction | 2026 |
| B2H Technical Rope Training Limited | Education | 2023 |
| Babil Care Limited | Health & social care | 2022 |
| Babil Properties Limited | Real estate | 2024 |
| Babypanda Clothing Ltd | Wholesale & retail | 2026 |