| Ahmed Bros FBA Limited | Wholesale & retail | 2025 |
| Ahmed Builders (NW) Ltd | Construction | 2016 |
| Ahmmed Imaging Ltd | Health & social care | 2025 |
| Ahsanul HAQ Limited | Health & social care | 2005 |
| Ahsummit Ltd | Households | 2026 |
| AHV Investments Ltd | Real estate | 2025 |
| AI Automation Corporation Ltd | Information & communication | 2024 |
| AI CHA Joy Limited | Wholesale & retail | 2022 |
| AI Couriers Limited | Transport & logistics | 2021 |
| AI Designs Limited | Construction | 2014 |
| AI Laboratories Ltd | Information & communication | 2024 |
| AI Tax Diagnostics Ltd | Information & communication | 2023 |
| AIB Security Ltd | Administrative & support | 2018 |
| AID Engineering Consultancy Ltd | Construction | 2020 |
| Aiden Transport Ltd | Transport & logistics | 2024 |
| Aidencairns Ltd | Transport & logistics | 2024 |
| Aidify Global CIC | Administrative & support | 2025 |
| AIE Preston Limited | Manufacturing | 2025 |
| AIF Medical Services Ltd | Health & social care | 2017 |
| Aifantasyfootball Ltd | Information & communication | 2025 |
| Aijs Properties Limited | Real estate | 2024 |
| Ailsa HR Consultancy Limited | Administrative & support | 2012 |
| Ailze Ltd | Administrative & support | 2022 |
| AIM (Preston) Limited | Construction | 2024 |
| AIM (Services) Limited | Professional & scientific | 2013 |
| AIM Assets Limited | Construction | 2025 |
| AIM Capital Limited | Real estate | 1967 |
| AIM Construction Limited | Construction | 2022 |
| AIM Equities Limited | Financial services | 2025 |
| AIM Investment Properties Limited | Real estate | 2024 |
| AIM Land Limited | Construction | 2018 |
| AIM Metric Limited | Construction | 2024 |
| AIM RE Limited | Construction | 2025 |
| AIM Realty Limited | Construction | 2024 |
| AIM Strategic Land Limited | Construction | 2026 |
| Aimedix Ltd | Health & social care | 2024 |
| Aimee Abigail Leigh and Associates Ltd | Arts & recreation | 2013 |
| Aina Abdullah Limited | Wholesale & retail | 2025 |
| Aina Beauty Limited | Wholesale & retail | 2025 |
| Aina Essentials Ltd | Wholesale & retail | 2025 |
| Aina Ventures Limited | Wholesale & retail | 2025 |
| Aincite Limited | Administrative & support | 2019 |
| Ainoto Limited | Information & communication | 2022 |
| Ainsworth Accountants Limited | Professional & scientific | 2005 |
| Ainsworth Conferences Limited | Real estate | 2020 |
| Ainsworth Contractor Limited | Transport & logistics | 2025 |
| Ainsworth Finishing Company Limited | Manufacturing | 2000 |
| Air Conditioning Services (NW) Limited | Construction | 2006 |
| Air Select Limited | Administrative & support | 2009 |
| Airedale Digital Ltd | Information & communication | 2019 |
| Airiba Works Ltd | Wholesale & retail | 2025 |
| Airlink Projects BG Ltd | Professional & scientific | 2023 |
| Airmeith Ltd | Health & social care | 2024 |
| Airport Transfers Group Limited | Transport & logistics | 2016 |
| Airport Transfers Lancashire Limited | Transport & logistics | 2023 |
| Airprime Ltd | Professional & scientific | 2002 |
| Airrie Unmanned Aircraft Services Limited | Manufacturing | 2021 |
| Airs Asbestos Removal (2014) Ltd | Water & waste | 2014 |
| Airtools Limited | Extraterritorial | 2002 |
| Airxygen Ltd | Wholesale & retail | 2025 |
| Aisling Fanatic Ltd | Wholesale & retail | 2023 |
| Aizah Traders Ltd | Wholesale & retail | 2026 |
| Aizome Limited | Professional & scientific | 2018 |
| AJ & East Rentals Ltd | Administrative & support | 2025 |
| AJ & MV Transport Ltd | Transport & logistics | 2020 |
| AJ Contracting Limited | Construction | 2025 |
| AJ Nicholson Financial Consulting Ltd | Financial services | 2017 |
| AJ Snibson Ltd | Hospitality | 2025 |
| AJ Vision Services Ltd | Health & social care | 2021 |
| AJ Watson Civils Ltd | Construction | 2026 |
| Aj's at Huntleys Ltd | Hospitality | 2026 |
| Aj-Tcg Ltd | Wholesale & retail | 2023 |
| Ajaskew Holdings Ltd | Financial services | 2026 |
| Ajaz Ahmed Shafi Ltd | Extraterritorial | 2022 |
| AJB Electrical (North West) Limited | Construction | 2023 |
| AJB Hydraulics Limited | Financial services | 2018 |
| Ajddjd LLP | | 2022 |
| Ajem Group Ltd | Wholesale & retail | 2026 |
| AJG Regulatory Solutions Ltd | Professional & scientific | 2025 |
| AJH Car Body Repair Ltd | Wholesale & retail | 2023 |
| AJJ (Holdings) Limited | Financial services | 2019 |
| Ajjc Developments Ltd | Real estate | 2025 |
| AJL Wellness Limited | Arts & recreation | 2025 |
| AJM Creative Ltd | Information & communication | 2019 |
| AJP Anaesthetics Limited | Health & social care | 2022 |
| AJR Events Ltd | Construction | 2015 |
| AJR Projects Ltd | Administrative & support | 2011 |
| Ajstrades Ltd | Wholesale & retail | 2024 |
| Ajuk (Northwest) Limited | Other services | 2003 |
| AJW Contractors Ltd | Construction | 2023 |
| AK Bespoke Installations Limited | Construction | 2020 |
| AK Carpets Limited | Wholesale & retail | 1999 |
| AK Conglomerate Ltd | Financial services | 2018 |
| AK Fire and Safety Ltd | Public administration | 2018 |
| AK Joinery Works Ltd | Construction | 2025 |
| AK Pound Plus Ltd | Wholesale & retail | 2026 |
| AK Stainless Holdings Limited | Financial services | 2024 |
| AK Supplies Lancashire Limited | Hospitality | 2018 |
| AK Tours Limited | Transport & logistics | 2019 |
| Ak's Preston Ltd | Information & communication | 2019 |