| Adrian Smith Wealth Management Limited | Financial services | 2015 |
| Adrocor Limited | Information & communication | 2014 |
| Ads-Mbo Ltd | Administrative & support | 2025 |
| Adsuk Ltd | Administrative & support | 2016 |
| Adteam Properties Ltd | Construction | 2023 |
| Advadec Decorating Ltd | Construction | 2022 |
| Advance Business Services Ltd | Professional & scientific | 2018 |
| Advance Operations Ltd | Professional & scientific | 2025 |
| Advance Performance Group Limited | Professional & scientific | 2007 |
| Advance Performance Limited | Professional & scientific | 2007 |
| Advance Pubs Ltd | Administrative & support | 2017 |
| Advanced Arboriculture Training Ltd | Agriculture & fishing | 2019 |
| Advanced Connectivity Ltd | Construction | 2023 |
| Advanced Heating Spares and Controls Limited | Wholesale & retail | 2010 |
| Advanced Plumbing & Maintenance Limited | Construction | 2013 |
| Adventure Marine Yachting Ltd | Extraterritorial | 2024 |
| Adventures and Tours Limited | Extraterritorial | 2022 |
| Advising Safety Ltd | Professional & scientific | 2022 |
| ADZ Distribution Ltd | Wholesale & retail | 2018 |
| AE Crane&Plant Hire Ltd | Manufacturing | 2020 |
| Aelia Property Ltd | Real estate | 2023 |
| Aerodynamics Consultants Ltd | Administrative & support | 2010 |
| Aerolux Holdings Limited | Financial services | 2025 |
| Aeviarch Ltd | Wholesale & retail | 2023 |
| AEY Vision Limited | Information & communication | 2026 |
| AFD Holdings Ltd | Financial services | 2022 |
| AFD Systems Limited | Manufacturing | 2009 |
| AFD Training Academy CIC | Administrative & support | 2026 |
| AFF Digital Enterprises Limited | Information & communication | 2020 |
| Affective Answers Limited | Health & social care | 2013 |
| Afghan Balkh Ltd | Wholesale & retail | 2025 |
| Afinan UK Limited | Extraterritorial | 2017 |
| African Foodies Ltd | Wholesale & retail | 2024 |
| AFS Advocate Financial Services Limited | Financial services | 2005 |
| Afterdecree Limited | Real estate | 1996 |
| Afterglow Showdogs Limited | Other services | 2025 |
| AG Pro Trading Ltd | Wholesale & retail | 2024 |
| AGA Yachting Limited | Extraterritorial | 2023 |
| AGB Services (NW) Ltd | Transport & logistics | 2026 |
| Agents Green Limited | Administrative & support | 2017 |
| Aggybear Ltd | Financial services | 2019 |
| Aggybear Properties Ltd | Real estate | 2023 |
| Agileap Limited | Information & communication | 2019 |
| Agpi Ltd | Real estate | 2025 |
| Agrimark Consulting Limited | Information & communication | 2018 |
| Agrocare UK Limited | Agriculture & fishing | 2022 |
| AGT Systems Ltd | Information & communication | 2009 |
| Agunic IV Limited | Extraterritorial | 2026 |
| AH Vision Ltd | Wholesale & retail | 2026 |
| AHA Pharma Limited | Other services | 2022 |
| AHL Developments Ltd | Real estate | 2024 |
| Ahron Ltd | Hospitality | 2026 |
| AI Business Marketing Ltd | Professional & scientific | 2026 |
| AIB Estate Planning Ltd | Professional & scientific | 2021 |
| Aidan Douglas Limited | Arts & recreation | 2013 |
| AIM 2 Care Training Limited | Education | 2018 |
| AIM Environmental Services Ltd | Water & waste | 2021 |
| Aintree Garages Ltd | Wholesale & retail | 2008 |
| Aintree Property Services Ltd | Real estate | 2022 |
| Air Charter & Travel Limited | Transport & logistics | 1992 |
| Air Navigation and Trading Company Limited | Administrative & support | 1947 |
| Air Training Club Aviation Limited | Transport & logistics | 2013 |
| Airborn Vision Limited | Professional & scientific | 2011 |
| Aireys Properties Ltd | Real estate | 2026 |
| Airframe Offices Ltd | Real estate | 2019 |
| Airframe Properties Limited | Real estate | 2019 |
| Airport Car Wash Ltd | Administrative & support | 2025 |
| Airtech Yachting Ltd | Extraterritorial | 2024 |
| Aisha Beauty Saloon Ltd | Other services | 2025 |
| Aisling Property Limited | Real estate | 2017 |
| Aisling Property Management Ltd | Real estate | 2025 |
| AJ Dynamics Limited | Manufacturing | 2015 |
| AJ Ecology Services Ltd | Professional & scientific | 2026 |
| AJ Fylde Solutions Ltd | Arts & recreation | 2026 |
| AJ Hudson Property Limited | Real estate | 2019 |
| AJ Properties Blackpool Ltd | Real estate | 2024 |
| AJ2000 Limited | Real estate | 2024 |
| AJ8 Ltd | Wholesale & retail | 2024 |
| AJA Griffin Limited | Wholesale & retail | 2025 |
| Ajatech Limited | Information & communication | 2018 |
| Ajax CHC Ltd | Health & social care | 2021 |
| AJB Associates Limited | Construction | 2021 |
| Ajeet Singh PVT Ltd | Wholesale & retail | 2024 |
| AJH Associates (Blackpool) Limited | Administrative & support | 2010 |
| AJM Catering Limited | Hospitality | 2023 |
| AJN Consulting Solutions Limited | Information & communication | 2013 |
| AJP Safety Services Ltd | Professional & scientific | 2023 |
| AJP Social Studio Ltd | Professional & scientific | 2026 |
| AJP Software Solutions Limited | Information & communication | 2019 |
| AJR Property Limited | Real estate | 2016 |
| Ajrl Enterprises Limited | Wholesale & retail | 2025 |
| AJS Properties North West Ltd | Real estate | 2021 |
| AJS Vending Limited | Hospitality | 2006 |
| AJT Entertainment Limited | Arts & recreation | 2018 |
| AK Food Supplier Limited | Wholesale & retail | 2023 |
| Akash Tandoori Blackpool Limited | Hospitality | 2018 |
| Akdeniz Yachting GB Limited | Extraterritorial | 2025 |
| AKH Estates Ltd | Real estate | 2024 |
| Akimbo Core Ltd | Information & communication | 2021 |
| Akshire Limited | Real estate | 2018 |