| Acoustic GRG Products Limited | Construction | 2001 |
| Acpilates Ltd | Arts & recreation | 2024 |
| Acrise Estates Ltd | Real estate | 2017 |
| Acrise Place (Management) Limited | Real estate | 1988 |
| Active Freight Solutions Limited | Transport & logistics | 2020 |
| Activescapes Ltd | Administrative & support | 2025 |
| Acuaware Ltd | Health & social care | 2024 |
| Acula Creations Limited | Manufacturing | 2013 |
| ACW Accounts Limited | Professional & scientific | 2009 |
| AD8 Consultancy Ltd | Professional & scientific | 2015 |
| Adam Corporate Limited | Professional & scientific | 2003 |
| Adam Corporate Services Limited | Professional & scientific | 1994 |
| Adam in Eden Limited | Professional & scientific | 1998 |
| ADAM01 Ltd | Other services | 2026 |
| Adammm Ltd | Other services | 2021 |
| Adex International Technologies Ltd | Information & communication | 2019 |
| Admiral Harvey Limited | Hospitality | 2019 |
| Adrych Ltd | Professional & scientific | 2015 |
| ADS Properties Services Limited | Real estate | 2021 |
| Advance People Services Ltd | Professional & scientific | 2005 |
| Advanced GAS, Heating & Plumbing Ltd | Construction | 2017 |
| Advisario Limited | Professional & scientific | 2012 |
| Advocating International Limited | Information & communication | 2009 |
| Aesthetics AKA Ltd | Health & social care | 2023 |
| AF Assist Ltd | Professional & scientific | 2023 |
| Affect Fire Protection Ltd | Manufacturing | 2019 |
| Afflatech Limited | Information & communication | 2013 |
| Afra Ltd | Wholesale & retail | 2022 |
| Afsana Press Ltd | Information & communication | 2021 |
| AGB Electrical Services Kent Limited | Construction | 2026 |
| Aggi Mazur Ltd | Wholesale & retail | 2024 |
| Aggi's Bridal House Ltd | Wholesale & retail | 2025 |
| Agolu Ltd | Wholesale & retail | 2026 |
| Agrippa Analytics Ltd | Information & communication | 2020 |
| Agriscapes Ltd | Administrative & support | 2019 |
| AH Property (East Kent) Limited | Real estate | 2024 |
| Ahc.Online Limited | Professional & scientific | 2023 |
| Ajeef Care Plus Ltd | Health & social care | 2023 |
| Akniv Ltd | Professional & scientific | 2025 |
| AL Car Cleaning Ltd | Administrative & support | 2024 |
| Alan Barham Business Support Services Limited | Other services | 2013 |
| Alan Creed Recruitment Limited | Administrative & support | 2026 |
| Alchemy Aotearoa Ltd | Wholesale & retail | 2025 |
| Alder Associates Ltd | Health & social care | 2020 |
| Aleksandra Rozanska Ltd | Other services | 2023 |
| Alex Maclaren Associates Ltd | Education | 2026 |
| Alexia Pflege Ltd. | Professional & scientific | 2015 |
| Alhas UK Import & Export Limited | Real estate | 2018 |
| Alicia Baker Consultancy Ltd | Financial services | 2016 |
| Alignment Coaching Ltd | Other services | 2025 |
| Alinur Ltd | Hospitality | 2024 |
| ALL Abroad Pet Travel Ltd | Transport & logistics | 2023 |
| ALL Bikes Limited | Wholesale & retail | 2013 |
| ALL Building Aspects Limited | Construction | 2009 |
| ALL IT Services (UK) Limited | Information & communication | 2005 |
| ALL the Lovely Things Ltd | Professional & scientific | 2022 |
| ALL Things Render Limited | Construction | 2026 |
| ALL Your Garden Needs Limited | Administrative & support | 2003 |
| Allberry Wells Garden Design LLP | | 2025 |
| Allbuild Canterbury Limited | Construction | 2014 |
| Allecs Limited | Administrative & support | 2006 |
| Allen Garden Solutions Ltd | Administrative & support | 2014 |
| Allengar Ltd | Wholesale & retail | 2025 |
| Alliance Building Company Contracts Ltd | Construction | 2013 |
| Alliance Property Maintenance Services Limited | Construction | 2003 |
| Alongside Africa | Education | 2010 |
| Alpha Resourcing LP | | 2007 |
| Alphaveil Limited | Wholesale & retail | 2017 |
| Altiustech Health UK Ltd | Information & communication | 2026 |
| Alture Treks Limited | Administrative & support | 2025 |
| AM Fife Services Limited | Hospitality | 2017 |
| AM Nuclear Decommissioning Consultancy Ltd | Professional & scientific | 2023 |
| AMA Hair Extension Academy Ltd | Education | 2026 |
| Amarasabia Ltd | Other services | 2026 |
| Amber Rescue Ltd | Wholesale & retail | 2020 |
| Amberglaze (Kent) Ltd | Construction | 2014 |
| Amco Construction Consultants Ltd. | Professional & scientific | 2019 |
| American Shop 1 Ltd | Wholesale & retail | 2025 |
| Amira Technologies Ltd | Professional & scientific | 2015 |
| Amma Massage Ltd | Other services | 2020 |
| Amulet Mortgages Ltd | Financial services | 2018 |
| Amulet Property Holdings Ltd | Real estate | 2020 |
| Anacore Ltd | Information & communication | 2025 |
| Anacore Solutions Ltd | Information & communication | 2002 |
| Ancestors Limited | Financial services | 2014 |
| Ancestors of Dover Partners LLP | | 2013 |
| Ancmanufacturing Ltd | Manufacturing | 2020 |
| AND Gather CIC | Health & social care | 2025 |
| Andre Gilbert Ltd | Professional & scientific | 2022 |
| Andrew Jaynes Ltd | Manufacturing | 2004 |
| Andrew S Consulting Ltd | Professional & scientific | 2019 |
| Andrew Wall Pro Bassist Limited | Health & social care | 2014 |
| Andy Devereux GAS Services Ltd | Professional & scientific | 2022 |
| Andy Graphix Limited | Administrative & support | 2002 |
| Andybusiness Limited | Other services | 2016 |
| Angel Heights Hawkinge Limited | Households | 2005 |
| Anitelimart Ltd | Health & social care | 2018 |
| Antario Ltd. | Administrative & support | 2008 |
| AOK King Plumbing and Heating Ltd | Wholesale & retail | 2025 |
| AP Infinite Solutions Limited | Information & communication | 2015 |