| Ai-Pro Digital PVT Ltd | Information & communication | 2023 |
| Aidnhol Limited | Real estate | 2023 |
| AIG Foods House Ltd | Manufacturing | 2025 |
| Aigle Ventures Limited | Real estate | 2006 |
| Aihomes Limited | Wholesale & retail | 2017 |
| Ailsida Hotels Limited | Hospitality | 1988 |
| Ailsida Property Investment Co. Limited | Real estate | 1986 |
| Aimava Limited | Administrative & support | 2014 |
| Aimm Consultancy Ltd | Other services | 2023 |
| Air Charter (Southern Air) Limited | Hospitality | 1991 |
| Aira Investments Limited | Real estate | 2016 |
| Airhead UK Property Management Limited | Real estate | 2017 |
| Airquake Audio Ltd | Information & communication | 2021 |
| Aixrepublic Ltd | Information & communication | 2025 |
| AJ South Carpentry and Construction Ltd | Construction | 2019 |
| AJ Sussex Construction Ltd | Construction | 2015 |
| Ajax 168 Ltd | Professional & scientific | 2022 |
| AJD Contracting Ltd | Public administration | 2019 |
| AJL Dental Limited | Health & social care | 2024 |
| AJT Invest Ltd | Real estate | 2019 |
| AJT Technologies Limited | Information & communication | 2023 |
| AJW Healthcare Limited | Health & social care | 2021 |
| AJW Strategic Advisory Ltd | Professional & scientific | 2023 |
| AK Creative House Ltd | Arts & recreation | 2025 |
| AK Decorating Limited | Construction | 2016 |
| AK Rebellion Ltd | Education | 2021 |
| Akayazdani Limited | Health & social care | 2026 |
| Akbay Property Limited | Real estate | 2020 |
| Akhet Limited | Financial services | 2021 |
| Akhund Consulting Limited | Professional & scientific | 2021 |
| Akkar Limited | Administrative & support | 2014 |
| Akmsm Limited | Health & social care | 2021 |
| Akolade Dental Limited | Health & social care | 2022 |
| Akolade Properties Limited | Real estate | 2024 |
| AKT Construction Ltd | Construction | 2014 |
| AKT Investments Limited | Real estate | 2014 |
| AL Sinclair Editing Ltd | Information & communication | 2010 |
| AL Wills Entertainment Ltd | Hospitality | 2025 |
| ALA Smiles Limited | Health & social care | 2026 |
| Alaina Louise Ltd | Public administration | 2021 |
| Alam Brothers & Co Cash & Carry Ltd | Wholesale & retail | 2024 |
| Albany Property Limited | Real estate | 1997 |
| Albemarle Mansions (Hove) Limited | Households | 1996 |
| Albion Financial Services Ltd | Financial services | 2025 |
| Albion House VG Limited | Real estate | 2024 |
| Albion House VG Rentals Limited | Real estate | 2025 |
| Albright Commercial Cleaning Limited | Administrative & support | 2016 |
| Aldersgate Court Management Company Limited | Households | 1990 |
| Aldridge Ritchie Capital Ltd | Professional & scientific | 2025 |
| Alencon Flat Management Limited | Real estate | 1993 |
| Alex Consultation Ltd | Health & social care | 2023 |
| Alex Legendre Consultancy Ltd | Professional & scientific | 2022 |
| Alex Mullan Ltd | Professional & scientific | 2025 |
| Alex Turner Ltd | Information & communication | 2022 |
| Alex Young Consulting Limited | Professional & scientific | 2021 |
| Alexander Benjamin Limited | Administrative & support | 2008 |
| Alexander James Scott Ltd | Professional & scientific | 2017 |
| ALI Amir Consultancy Ltd | Health & social care | 2021 |
| ALI Asghar Limited | Hospitality | 2025 |
| ALI Noori Dental Limited | Health & social care | 2026 |
| Alias Music and Community Projects C.I.C. | Information & communication | 2014 |
| Alias Music Events Ltd | Arts & recreation | 2022 |
| Alice Burden Coaching Ltd | Professional & scientific | 2023 |
| Alimentarius Limited | Arts & recreation | 2003 |
| Alison Group Limited | Information & communication | 2006 |
| Alito Investment Group Ltd | Financial services | 2026 |
| Alixia Properties Ltd | Real estate | 2014 |
| ALL About the E Limited | Professional & scientific | 2021 |
| ALL Access Accountancy Limited | Professional & scientific | 2025 |
| ALL Available Space Ltd | Information & communication | 2014 |
| ALL Blue Property Services Ltd | Real estate | 2026 |
| ALL Cabling Limited | Construction | 2018 |
| ALL Good Folks Limited | Arts & recreation | 2021 |
| ALL Household Jobs Ltd | Information & communication | 2025 |
| ALL YOU Need Prime Ltd | Wholesale & retail | 2018 |
| Allen Windows, Doors & Maintenance Ltd | Construction | 2026 |
| Allez Productions Ltd | Information & communication | 2026 |
| Alliance Moving Services Ltd | Transport & logistics | 2012 |
| Alljoinedup Limited | Information & communication | 2018 |
| Allora (Hove) Ltd | Hospitality | 2021 |
| Allowmeto Limited | Real estate | 2020 |
| Allstart Limited | Wholesale & retail | 2012 |
| Alltrade Distribution Ltd | Wholesale & retail | 1995 |
| Alltrade Group Holdings Limited | Financial services | 2024 |
| Alma Restaurants Ltd | Hospitality | 2022 |
| Alma View Ltd | Real estate | 2024 |
| Almanar KFT Limited | Hospitality | 2024 |
| ALO Profici Consulting Limited | Professional & scientific | 2015 |
| Aloha Films Limited | Information & communication | 2005 |
| ALP Dent Limited | Health & social care | 2023 |
| Alpha Key Limited | Information & communication | 2019 |
| Alpha Leader Consulting Limited | Professional & scientific | 2018 |
| Alpha MAN Life Limited | Information & communication | 2015 |
| Alpha Residential Limited | Professional & scientific | 2008 |
| Alpha Servicing Limited | Wholesale & retail | 2024 |
| Alphabet Publishing Limited | Information & communication | 1996 |
| Alphablit Limited | Information & communication | 2016 |
| Alpine Access Services Ltd | Other services | 2022 |
| Alrayan Mini Market Ltd | Wholesale & retail | 2021 |
| Altay Marketing Ltd | Professional & scientific | 2019 |