| Albert R Pearson Builders and Developers Ltd | Construction | 2024 |
| Albion Hastings Ltd | Hospitality | 2015 |
| Albion Industry Ltd | Information & communication | 2024 |
| Albion Pies Hastings Ltd | Hospitality | 2024 |
| Albion PUB Hastings Ltd | Hospitality | 2024 |
| Alchary Ltd | Transport & logistics | 2025 |
| Alchemy Designs Limited | Information & communication | 2009 |
| Aldurtron Ltd | Information & communication | 2018 |
| Alectic Limited | Information & communication | 2019 |
| Alex Lingard Contractors Limited | Agriculture & fishing | 2024 |
| Alexander Music Ltd | Information & communication | 2025 |
| Alexandra Court (Hastings) Limited | Households | 1998 |
| Alexandrageo Care Limited | Health & social care | 2016 |
| Alfa Electric Limited | Construction | 2002 |
| Alfaar Ltd | Wholesale & retail | 2026 |
| ALI Property Services Ltd | Real estate | 2023 |
| Alikat Capital Partners Limited | Professional & scientific | 2025 |
| Alikat Group Limited | Professional & scientific | 2023 |
| ALL Things Doggy Ltd | Other services | 2025 |
| Alliance Performance Healthcare Ltd | Health & social care | 2015 |
| Allook LLP | | 2012 |
| Ally Transs Ltd | Transport & logistics | 2019 |
| Alma Digital Ltd | Professional & scientific | 2026 |
| Alpha Scaffolding Services Ltd | Construction | 2024 |
| AM Pleasant Group Ltd | Hospitality | 2026 |
| AMAC1 Ltd | Hospitality | 2021 |
| Amacuk Limited | Wholesale & retail | 2012 |
| Amatuni Ltd | Hospitality | 2022 |
| Amazing Productions Limited | Information & communication | 2014 |
| Amherst 38 Limited | Households | 2013 |
| Amherst Road Management Company Limited | Households | 2019 |
| Amici Art Ltd | Arts & recreation | 2025 |
| Amici Studio CIC | Education | 2025 |
| Amoun Services Ltd | Professional & scientific | 2014 |
| Amundsen OMEGA3 Limited | | 2008 |
| AMY Sweets Cafe Limited | Hospitality | 2024 |
| Anchorwatt Limited | Professional & scientific | 2025 |
| Anda LH Limited | Hospitality | 2022 |
| Anderson & Hunter Limited | Construction | 2022 |
| Andra Trading Limited | Manufacturing | 2026 |
| Andreia's Cleaning Limited | Administrative & support | 2025 |
| Andrew Moore Consulting Limited | Professional & scientific | 2014 |
| Anglex Developments Ltd | Manufacturing | 2024 |
| Anglo International Student Centre Limited | Education | 2022 |
| Anglo-Sino Education Limited | Education | 2020 |
| Angrygrandad Limited | Wholesale & retail | 2024 |
| Annabelle Briscall Consulting Ltd | Professional & scientific | 2026 |
| Annagee Limited | Wholesale & retail | 2005 |
| Annasvintagefinds Ltd | Wholesale & retail | 2020 |
| Anne Hamilton Health & Beauty Limited | Administrative & support | 2005 |
| Antano Kandroto Paramos Fondas | Other services | 2024 |
| Aoyagi Limited | Administrative & support | 2026 |
| Appetyte Limited | Information & communication | 2018 |
| Apple Capital Ltd | Information & communication | 2020 |
| Application Systems Ltd. | Information & communication | 2023 |
| Applied Joinery Ltd | Manufacturing | 2024 |
| Aptlevel Management Limited | Professional & scientific | 2015 |
| APX Fire & Security Limited | Manufacturing | 2003 |
| APX Mechanical & Electrical Limited | Construction | 2018 |
| Aqiro Limited | Wholesale & retail | 2025 |
| Aqua Shield Suppression Limited | Construction | 2025 |
| Aquacor Limited | Real estate | 2013 |
| Arbat Capital Advisory Services Ltd | Professional & scientific | 2003 |
| Arbourvale (Area B) Management Company Limited | Households | 2005 |
| Arcadia Estate Services Ltd | Administrative & support | 2015 |
| Arcool Limited | Professional & scientific | 2002 |
| Ardicure Ltd | Wholesale & retail | 2024 |
| AREACHECK123 Limited | Wholesale & retail | 2009 |
| Argentière Advisors Limited | Professional & scientific | 2015 |
| Argonath Limited | Financial services | 2020 |
| Arko Property Management Ltd | Real estate | 2009 |
| Arkwhites Ltd | Wholesale & retail | 2023 |
| Arma Security Consultants Ltd | Administrative & support | 2021 |
| Arrow Waste Limited | Water & waste | 2018 |
| Arrusa Ltd | Wholesale & retail | 2026 |
| Art-Write (Hythe) Limited | Wholesale & retail | 2003 |
| Arthurguy.Co.Uk Ltd | Information & communication | 2011 |
| Arts and Culture Consultancy Limited | Arts & recreation | 2020 |
| Artugsuk Limited | Wholesale & retail | 2025 |
| Arwyn Keast Ltd | Information & communication | 2011 |
| Ascent Propco 1 Ltd | Real estate | 2017 |
| Ascent Propco 2 Ltd | Real estate | 2018 |
| Ascent Propco 3 Ltd | Real estate | 2018 |
| Ascent Propco 4 Ltd | Real estate | 2019 |
| Ascent Propco 5 Ltd | Real estate | 2019 |
| Ascent Propco 6 Ltd | Real estate | 2021 |
| Ascent Propco 7 Ltd | Real estate | 2024 |
| Ascent Real Properties Limited | Real estate | 2017 |
| ASE 100 Limited | Other services | 2025 |
| Ashdown Hurrey Auditors Limited | Professional & scientific | 2015 |
| Ashdown Hurrey Solutions Ltd | Professional & scientific | 2015 |
| Ashley Court (ST. Leonards on Sea) Residents Limited | Households | 1990 |
| Askolay Limited | Information & communication | 2023 |
| ASL Group Sussex Limited | Financial services | 2024 |
| ASL Recruitment Limited | Administrative & support | 1998 |
| ASL Technical Ltd | Administrative & support | 2022 |
| Asmbl Events Ltd | Hospitality | 2025 |
| Asta House Freehold Limited | Households | 2017 |
| Astral Services UK Limited | Hospitality | 2001 |
| Astrid Brisson Ltd | Professional & scientific | 2021 |