| ANN Grant Consultancy Limited | Administrative & support | 2017 |
| ANN Street Limited Liability Partnership | | 2014 |
| Anna Coane Limited | Information & communication | 2007 |
| Anna Robert Developments Ltd | Real estate | 2023 |
| Anna Spragg Consultancy Ltd | Professional & scientific | 2021 |
| Anna Wood Hygienist Ltd | Health & social care | 2016 |
| Annabelles Wigs Ltd | Other services | 2011 |
| Anniek Verholt Ltd | Arts & recreation | 2022 |
| Annis IT Limited | Information & communication | 2013 |
| Annlytical Media Ltd | Information & communication | 2015 |
| Anokimobi Holdings Ltd | Real estate | 2007 |
| Anokimobi Limited | Wholesale & retail | 2003 |
| Anomalous Properties Ltd | Real estate | 2021 |
| Another Bearded Designer Limited | Information & communication | 2009 |
| Another Plan Ltd | Manufacturing | 2019 |
| Anston Building Company Limited | Construction | 2017 |
| Anston Estates Sussex Limited | Real estate | 2017 |
| Anston Investments Sussex Limited | Real estate | 2017 |
| Anston Properties Sussex Limited | Real estate | 2017 |
| Anston Realty Sussex Limited | Real estate | 2017 |
| Anstone Group Limited | Construction | 2025 |
| Anstone RHS Limited | Financial services | 2025 |
| ANT and BEE Ltd | Administrative & support | 2017 |
| Antee Limited | Professional & scientific | 2012 |
| Anthills HQ Limited | Wholesale & retail | 2023 |
| Anthony Cole Associates Ltd | Administrative & support | 2013 |
| Anthony Creative Enterprises Limited | Information & communication | 1996 |
| Anthony Foreman & Co. Limited | | 1971 |
| Anthony Pearce Services Limited | Administrative & support | 2023 |
| Anti - Graffiti Systems (UK) Limited | Extraterritorial | 2003 |
| Anti-Corruption Advisory Limited | Information & communication | 2017 |
| Anti-Graffiti Systems Limited | Administrative & support | 2002 |
| Anti-Real Media Ltd | Information & communication | 2022 |
| Antiva Professional Services Ltd | Information & communication | 2016 |
| Antivenin Games Ltd | Arts & recreation | 2023 |
| Antoine Consulting Limited | Professional & scientific | 2018 |
| Antownous Laundrette Ltd | Administrative & support | 2015 |
| Antoziggy Ltd | Health & social care | 2020 |
| Antrams Financial Services LLP | | 2009 |
| Antrams Holdings Limited | Professional & scientific | 2021 |
| Antrams Limited | Financial services | 2021 |
| Antrams Wealth Management Ltd | Financial services | 2010 |
| Antrim Partners Ltd | Professional & scientific | 2026 |
| Antskicks Ltd | Wholesale & retail | 2024 |
| Anville Creative Ltd | Information & communication | 2021 |
| ANY Old Icon Limited | Extraterritorial | 2005 |
| Anymore Games Ltd | Information & communication | 2024 |
| Anyon Build Construction Ltd | Construction | 2014 |
| Anysurface Ltd | Arts & recreation | 2021 |
| Anything IS Possible Media Limited | Professional & scientific | 2017 |
| Anzen Technology Systems Limited | Information & communication | 2018 |
| AON Rentals Ltd | Real estate | 2022 |
| AP Marine De-Carbonisation Ltd | Professional & scientific | 2025 |
| AP Spalding Protective Solutions Ltd | Administrative & support | 2007 |
| AP Steine Limited | Wholesale & retail | 2024 |
| Apalachicola Software Solutions Limited | Information & communication | 2012 |
| APC Care Limited | Health & social care | 2014 |
| APC Roofing and Property Maintenance Ltd | Construction | 2023 |
| APD Intellectual Property Ltd | Professional & scientific | 2026 |
| APE Creative Ltd | Professional & scientific | 2007 |
| APE Origins Ltd | Arts & recreation | 2025 |
| Apex Investments Group Ltd | Financial services | 2025 |
| Apex Production Vehicles Ltd | Transport & logistics | 2026 |
| Apex Structures Ltd | Construction | 2022 |
| Apiary by Bell Ltd | Agriculture & fishing | 2021 |
| Apiex Ltd | Information & communication | 2021 |
| Apina Solutions Ltd | Information & communication | 2022 |
| Aplacetobe Ltd | Hospitality | 2016 |
| Apollo Audio Ltd | Information & communication | 2024 |
| Apollo Restorations Limited | Administrative & support | 2025 |
| Apollo's Path Ltd | Other services | 2026 |
| Apparel Technology Limited | Manufacturing | 2020 |
| Appetite Publicity Ltd | Professional & scientific | 2021 |
| Appetite Solutions Ltd | Information & communication | 2025 |
| Apphut Ltd | Information & communication | 2013 |
| Apple Tree Nursery Schools Limited | Extraterritorial | 2026 |
| Appletree Growth Ltd | Other services | 2010 |
| Applied Systems Europe Limited | Information & communication | 1999 |
| Applied Type Limited | Information & communication | 2013 |
| Applied UK Holdings I Limited | Information & communication | 2013 |
| Applied UK Holdings II Limited | Information & communication | 2013 |
| Applife Tech Ltd | Other services | 2026 |
| Appocalypse Limited | Information & communication | 2019 |
| Apps Accountancy Services Ltd | Professional & scientific | 2008 |
| Apps Paraplanning Services Ltd | Financial services | 2012 |
| Apptly Software Ltd | Information & communication | 2024 |
| APR Solutions Limited | Administrative & support | 2011 |
| Apricity Capital Partners Limited | Professional & scientific | 2026 |
| Apricity Wealth Management UK Ltd | Financial services | 2023 |
| Apricorn Investments Limited | Administrative & support | 2001 |
| April Baker Ltd | Health & social care | 2025 |
| APS Services (Sussex) Ltd | Construction | 2007 |
| APS Sussex Limited | Construction | 2015 |
| Apsley Consultancy Ltd | Professional & scientific | 2022 |
| Apyar Ltd | Hospitality | 2017 |
| AQ Training & Development Limited | Education | 2012 |
| Aqitas Limited | Information & communication | 2026 |
| Aqoc Ltd | Information & communication | 2025 |
| AQS Property Ltd | Real estate | 2025 |
| Aquabase Limited | Construction | 2025 |