| Atort Properties Ltd | Real estate | 2022 |
| Attributed Media Limited | Professional & scientific | 2020 |
| ATW Electrical Ltd | Construction | 2023 |
| AU Assist Ltd | Transport & logistics | 2020 |
| AU Finance Limited | Financial services | 2024 |
| Auction Line Limited | Information & communication | 2022 |
| Audacious Revolution Limited | Education | 2005 |
| Audio and Communication Technology Limited | Arts & recreation | 2013 |
| Audit Partners Ltd | Other services | 2017 |
| Audvik Labs Private Limited | Information & communication | 2025 |
| Augere Limited | Professional & scientific | 2018 |
| Augmented Haptics Ltd | Professional & scientific | 2021 |
| Augora Ltd | Information & communication | 2026 |
| AUM LAB Ltd | Manufacturing | 2026 |
| Aunty RAG Ltd | Manufacturing | 2011 |
| Aura Chester Limited | Other services | 2020 |
| Aureliant Limited | Professional & scientific | 2026 |
| Aurex Group UK Limited | Administrative & support | 2022 |
| Aurora Telecom UK Limited | Information & communication | 2016 |
| Austin END Ltd | Real estate | 2003 |
| Austin Technology Solutions Limited | Information & communication | 2021 |
| Australasian Recruitment Company Limited | Administrative & support | 2003 |
| Autichem Ltd | Professional & scientific | 2014 |
| Auto Real Ltd | Wholesale & retail | 2025 |
| Auto Travel Holdings Limited | Real estate | 2007 |
| Auto Union Warranties Limited | Manufacturing | 2016 |
| Auto Verification Technologies Ltd | Information & communication | 2024 |
| Auto-Tech Chester Ltd | Wholesale & retail | 2023 |
| AUTO365 Ltd | Wholesale & retail | 2020 |
| Autoday Limited | Professional & scientific | 1990 |
| Autoexpress 82 Ltd | Wholesale & retail | 2015 |
| Autogate Service and Maintenance Ltd | Other services | 2020 |
| Automation and Process Control Limited | Wholesale & retail | 2001 |
| Automotive Machine Tool Limited | Manufacturing | 2005 |
| Autoquality Limited | Wholesale & retail | 1996 |
| Autoshine Worx Ltd | Financial services | 2004 |
| Autosteer Direct Limited | Manufacturing | 2003 |
| Autumn Home Lettings Limited | Real estate | 2020 |
| Auxano Consult Limited | Administrative & support | 2011 |
| AV8 Human Factors Training Limited | Education | 2021 |
| AVA Contracting Ltd | Construction | 2026 |
| AVA Property Investments Ltd | Real estate | 2024 |
| Avail Projects Limited | Construction | 2014 |
| Avanity Limited | Manufacturing | 2020 |
| Avatar Fitness Ltd | Arts & recreation | 2019 |
| Aventail Systems Limited | Information & communication | 2007 |
| Aventura Ltd | Information & communication | 2003 |
| Avery GUD Payroll Ltd | Professional & scientific | 2021 |
| Aviagen Turkeys (Pension Trustee) Limited | Other services | 2022 |
| Aviasenze Limited | Professional & scientific | 2021 |
| Aviation SIM Training and Consulting Ltd | Transport & logistics | 2024 |
| Aviation Worldwide Training Ltd | Education | 2014 |
| Aviotti & Gobbato Ltd | Hospitality | 2018 |
| Avondale Village Store Limited | Wholesale & retail | 2006 |
| Avontour Limited | Real estate | 2018 |
| AW Arena Ltd | Education | 2025 |
| AW Foundry Spark Ltd | Professional & scientific | 2026 |
| Award Capital Limited | Professional & scientific | 2023 |
| Award House Limited | Real estate | 2023 |
| Award Limited | Real estate | 2022 |
| AWB Property Holdings Limited | Administrative & support | 2023 |
| AWB Property Investments Limited | Real estate | 2024 |
| AWC Images Limited | Real estate | 2014 |
| Awel Ynys RTM Company Limited | Households | 2021 |
| AWM Finance Limited | Professional & scientific | 2023 |
| Axia ASD Limited | Health & social care | 2012 |
| Axiomsense Ltd | Wholesale & retail | 2025 |
| Axis Management Partners Ltd | Professional & scientific | 2026 |
| Axis P.E.D Ltd | Professional & scientific | 1999 |
| Axis P.E.D Trustee Limited | Administrative & support | 2021 |
| Axpert Consulting Limited | Professional & scientific | 2009 |
| AXT Haus Ltd | Arts & recreation | 2024 |
| Aydain Kayan Shah Limited | Professional & scientific | 2017 |
| Aye,Done. Ltd | Information & communication | 2026 |
| Aygama Properties Ltd | Real estate | 2026 |
| Aynsley Services Limited | Financial services | 2004 |
| Azibi Ltd | Wholesale & retail | 2025 |
| Aztec Elec Ltd | Construction | 2023 |
| Aztec Property Projects Limited | Construction | 2020 |
| B & a Lonergan Properties Ltd | Real estate | 2021 |
| B & E Rentals Ltd | Real estate | 2020 |
| B & S Group Limited | Manufacturing | 1991 |
| B & T Pallets Limited | Construction | 2018 |
| B & W Automotive Limited | Wholesale & retail | 2011 |
| B City Roofing Ltd | Construction | 2025 |
| B K S Kitchens Ltd | Construction | 2018 |
| B Marsh Therapy Ltd | Health & social care | 2023 |
| B Pharma Ltd | Wholesale & retail | 2014 |
| B R Plumbing & Heating Services Limited | Construction | 2003 |
| B Richards Fire Protection Consultants Limited | Public administration | 2007 |
| B T Davies and SON Ltd | Construction | 2020 |
| B V Holdings Group Limited | Financial services | 2022 |
| B Z Advertising & Design Limited | Professional & scientific | 2001 |
| B&Bb Ltd | Other services | 2025 |
| B.S.C. Chester Ltd | Hospitality | 2026 |
| B03B Ltd | Manufacturing | 2020 |
| B2B Business Consultants Ltd | Administrative & support | 2020 |
| B2M - Bridge to Markets Limited | Wholesale & retail | 2018 |
| B8 Consulting Ltd | Information & communication | 2026 |
| Baby Club Cheshire Ltd | Education | 2020 |