| Algapelago Marine Limited | Agriculture & fishing | 2016 |
| Algarve Construction Ltd | Construction | 2020 |
| ALI Halal Meats Ltd | Hospitality | 2022 |
| Alison Smith Multisport Coaching Limited | Other services | 2023 |
| ALL Aspects Decorators Limited | Other services | 2010 |
| ALL Glamour Ltd | Arts & recreation | 2018 |
| ALL Nations (UK) Limited | Health & social care | 2013 |
| Allay Limited | Other services | 2004 |
| Allen Property Holdings Limited | Construction | 2017 |
| Allen Transport Limited | Transport & logistics | 2013 |
| Alliance Care Holding Limited | Health & social care | 2024 |
| Allied Refiners Limited | Wholesale & retail | 2014 |
| Almontree Limited | Information & communication | 2007 |
| ALP Accountancy Services Ltd | Professional & scientific | 2015 |
| Alpaso Ltd | Construction | 2024 |
| Alpha Bookkeeping Services Limited | Professional & scientific | 2023 |
| Alpha Omega Medics Ltd | Health & social care | 2020 |
| Alpha One Marketing Ltd | Administrative & support | 2019 |
| Alpha Tech Marketing Ltd | Wholesale & retail | 2025 |
| Alphafourzero Ltd | Construction | 2024 |
| Alpharize Limited | Other services | 2023 |
| ALT Systems Limited | Information & communication | 2012 |
| Altair Estates LDN Ltd | Administrative & support | 2025 |
| Altek Innovations Ltd | Real estate | 2017 |
| Alterproperties Limited | Real estate | 2023 |
| Altertech Limited | Information & communication | 2018 |
| Aluglass Services Ltd | Construction | 2024 |
| Alva Group Limited | Wholesale & retail | 2022 |
| Alvescapes Limited | Administrative & support | 2018 |
| Alwayssportplus Limited | Wholesale & retail | 2023 |
| Am/Pm Property Services Ltd. | Construction | 1994 |
| Amancay Limited | Real estate | 1989 |
| Amari Residential Care Ltd | Professional & scientific | 2022 |
| Amazing Airstreams Limited | Wholesale & retail | 2022 |
| Amber Property Company Limited | Real estate | 1996 |
| Ambercroft Ltd | Wholesale & retail | 2024 |
| Amberley Farm Limited | Real estate | 2023 |
| Amdipharm Limited | | 2020 |
| AME Rail Ltd | Construction | 2025 |
| Ameet Uberoi Limited | Professional & scientific | 2003 |
| American Biochemical and Pharmaceuticals Limited | Wholesale & retail | 1995 |
| Amery Plant Limited | Construction | 2009 |
| Amexo Properties Limited | Real estate | 2024 |
| Amfam Ltd | Financial services | 2025 |
| Amicus UK (Coatings) Ltd | Wholesale & retail | 2018 |
| Amirjan Food Ltd | Hospitality | 2022 |
| Amkn Limited | Information & communication | 2014 |
| Amnd Ltd | Real estate | 2017 |
| Amni Group Limited | Health & social care | 2021 |
| Amni Investments Ltd | Real estate | 2015 |
| Amni Property Limited | Real estate | 2022 |
| Amour Tutors Ltd | Administrative & support | 2025 |
| AMP2 Investments Limited | Real estate | 2017 |
| Amrabha Limited | Other services | 2009 |
| Amrk Limited | Financial services | 2025 |
| Anakay Commerce Ltd | Wholesale & retail | 2025 |
| Anakay Properties (Edward) Limited | Real estate | 2025 |
| Anakay Properties (Overdale) Limited | Real estate | 2018 |
| Anakay Properties Limited | Real estate | 2017 |
| Anantasri Property Limited | Real estate | 2026 |
| ANC Scaffolding Products Ltd | Construction | 2014 |
| Andetti Group Ltd | Real estate | 2025 |
| Andover Management Limited | Hospitality | 2016 |
| Andrea Ruffilli Architects Ltd | Professional & scientific | 2019 |
| Andrew Hall Property Ltd | Real estate | 2016 |
| Andys 92 Limited | Other services | 2025 |
| ANF First Co Ltd | Education | 2017 |
| Angel Khushi Limited | Real estate | 2018 |
| Anija Property Ltd | Real estate | 2020 |
| Anilka Limited | Real estate | 2017 |
| Animaforte Limited | Other services | 2025 |
| Anita Grace Wong Limited | Information & communication | 2018 |
| Anitabel Ltd | Manufacturing | 2021 |
| Anitan Limited | Professional & scientific | 2012 |
| Ankiya Partners Limited | Professional & scientific | 2025 |
| Anna's Kitchen Limited | Hospitality | 2011 |
| Annakiri Associates Limited | Financial services | 2024 |
| Annanya Limited | Wholesale & retail | 2013 |
| Annette Kathryn Interiors Limited | Professional & scientific | 2026 |
| Anora Capital Ltd | Wholesale & retail | 2025 |
| ANR Consultants Limited | Professional & scientific | 2012 |
| Anrok Limited | Financial services | 2021 |
| Anvaljo Ltd | Real estate | 2022 |
| Anwar Spine and Investment Limited | Financial services | 2023 |
| AOA Estates Ltd | Real estate | 2022 |
| AP Gardening Maintenance & Services Ltd | Administrative & support | 2018 |
| AP Project Consultancy Ltd | Professional & scientific | 2014 |
| Apexia Limited | Information & communication | 2025 |
| Apka Investment Limited | Financial services | 2017 |
| Apollo Board Limited | Financial services | 2014 |
| Apollo Global Solutions Ltd | Administrative & support | 2024 |
| Appidea INT Limited | Information & communication | 2018 |
| Apple Dental Studios Limited | Health & social care | 2007 |
| Apple Tree Family Properties Limited | Real estate | 2021 |
| Apropertycorp Limited | Real estate | 2001 |
| APT Medical Ltd | Health & social care | 2025 |
| APT Solutions TM Ltd | Transport & logistics | 2020 |
| Aquaswim Services Limited | Manufacturing | 2007 |
| Aquatico Ltd | Wholesale & retail | 2017 |
| Araujo Gardening Limited | Administrative & support | 2003 |