| AJ Amor Ltd | Extraterritorial | 2023 |
| AJA Management Services Limited | Financial services | 1987 |
| Ajarguz Projects Ltd | Construction | 2024 |
| AJH Finance Limited | Financial services | 2012 |
| AJK Housing Ltd | Real estate | 2023 |
| AJP Services (Corby) Limited | Construction | 2008 |
| AK Legacy Limited | Real estate | 2026 |
| Akkef Limited | Hospitality | 2026 |
| AKW Roofing and Cladding Specialists Ltd | Construction | 2024 |
| Al-Hadi Estates Limited | Real estate | 2026 |
| Alan Carson Fitness Ltd | Arts & recreation | 2014 |
| Alanex Limited | Manufacturing | 2009 |
| Alatt Engineering Solutions Ltd | Professional & scientific | 2026 |
| Albany Aggregates Desborough Limited | Water & waste | 2018 |
| Albert Skonieczny Ltd. | Transport & logistics | 2016 |
| Albri's Garage Limited | Wholesale & retail | 2025 |
| ALC Capital Ltd | Real estate | 2023 |
| Alchemy Libation Limited | Hospitality | 2024 |
| Aldema Ltd | Transport & logistics | 2026 |
| Alder Whiting Ltd | Wholesale & retail | 2021 |
| Alenva Ltd | Wholesale & retail | 2019 |
| Alex Construction Limited | Construction | 2017 |
| Alex D.A.G. Limited | Manufacturing | 2017 |
| Alex Fast Transport Ltd | Transport & logistics | 2024 |
| Alexander Future Property Limited | Real estate | 2021 |
| Alexander Transport Courier Haulage Ltd | Transport & logistics | 2014 |
| Alexcar Ltd | Wholesale & retail | 2023 |
| Alexmmm Services Ltd | Transport & logistics | 2023 |
| Alexsyl Consultancy Limited | Health & social care | 2014 |
| Alfa Detailing Ltd | Manufacturing | 2022 |
| Alfred Reader & Company Limited | Manufacturing | 1997 |
| Alibaba Conveyance Ltd | Transport & logistics | 2024 |
| Alice Blue Interiors Ltd | Professional & scientific | 2022 |
| Alice Fletcher Vintage Ltd | Wholesale & retail | 2020 |
| Alicia NSS Ltd | Transport & logistics | 2023 |
| Align Hire Ltd | Administrative & support | 2025 |
| Alignsearch Ltd | Administrative & support | 2025 |
| ALIN23 Ltd. | Construction | 2026 |
| Ali’S Investment Property Limited | Construction | 2025 |
| Allbrite Service Group Limited | Administrative & support | 1975 |
| Allder's Food Acres Ltd | Hospitality | 2022 |
| Alleyne Holdings Limited | Real estate | 2025 |
| Alliance Consult Ltd | Professional & scientific | 2025 |
| Alltourstransport Ltd | Transport & logistics | 2018 |
| Allworks Electrical Ltd | Construction | 2023 |
| Almatari Holdings Limited | Real estate | 2021 |
| Almi 04 Ltd | Transport & logistics | 2018 |
| Alois Pottinger UK Ltd | Wholesale & retail | 2012 |
| Alora Healthcare Services Ltd | Health & social care | 2022 |
| Alpha & Omega Care Limited | Hospitality | 2015 |
| Alpha Health & Social Care Services Ltd | Health & social care | 2014 |
| Alpha Homes Group Ltd | Real estate | 2024 |
| Alpha RP Developments Ltd | Real estate | 2021 |
| Alpha, Engineering, Projects and Operational Systems Limited | Professional & scientific | 2017 |
| Alrai Limited | Energy | 2009 |
| Altarnative Worlds Ltd | Administrative & support | 2026 |
| Alter EGO Atelier Ltd | Other services | 2011 |
| Alternative Catering Ltd | Hospitality | 2020 |
| Altiville Ltd | Arts & recreation | 2023 |
| Aluminium Rainflow Ltd | Wholesale & retail | 2017 |
| Aluralux Ltd | Wholesale & retail | 2025 |
| Alutaya Recruitment Limited | Administrative & support | 2023 |
| Am-Marc Trailers and Tarpaulins Ltd | Wholesale & retail | 2017 |
| AMA Nyarkoa & Company Ltd | Health & social care | 2022 |
| Amaarda Ltd | Wholesale & retail | 2024 |
| Amalia Logistik Ltd | Administrative & support | 2019 |
| Aman Transport Ltd | Transport & logistics | 2022 |
| AMB Driving Limited | Transport & logistics | 2014 |
| Ambar Group Limited | Financial services | 2018 |
| Amber Heat Sauna Limited | Wholesale & retail | 2024 |
| AMC 2026 Ltd | Wholesale & retail | 2026 |
| AMC Fasteners Ltd | Manufacturing | 2024 |
| Amcgservices Ltd | Information & communication | 2024 |
| Amelia Real Estate Holdings Ltd | Real estate | 2025 |
| AMELIOR8 Limited | Professional & scientific | 2007 |
| American Plus Ltd | Wholesale & retail | 2025 |
| Amet Property Limited | Real estate | 2016 |
| AMG Smart Limited | Manufacturing | 2015 |
| Amichaluk Ltd | Manufacturing | 2026 |
| Amiso Group Ltd | Other services | 2026 |
| Amison Dispute Resolutions Ltd | Administrative & support | 2015 |
| AMM Paintwork Limited | Wholesale & retail | 2018 |
| Ammcc Limited | Health & social care | 2022 |
| Amobcom Limited | Information & communication | 2025 |
| Amopat Logistics Limited | Transport & logistics | 2025 |
| Amos Referrals Limited | Professional & scientific | 2024 |
| Amouyan Invest Limited | Financial services | 2014 |
| AMP Services Ltd | Professional & scientific | 2023 |
| Amperetech Limited | Administrative & support | 2024 |
| Amperie Labs Limited | Information & communication | 2026 |
| Anaashe Ltd | Manufacturing | 2021 |
| Anaerobic Consulting Ltd | Professional & scientific | 2024 |
| Anbar Transport Ltd | Transport & logistics | 2025 |
| Anbt Consultancy Limited | Administrative & support | 2026 |
| Anchor Consulting Ltd | Public administration | 2025 |
| Anchor Pinnacle Ltd | Professional & scientific | 2025 |
| Andarah Properties Limited | Real estate | 2021 |
| Andis Construction Ltd | Construction | 2025 |
| Andrei Cirjan Ltd | Transport & logistics | 2024 |
| Andrei Gosman Ltd | Wholesale & retail | 2017 |