| Astra Distribution Group Ltd | Wholesale & retail | 2025 |
| Astra Investment Group Ltd | Financial services | 2021 |
| Astra Pharma Stoke Limited | Wholesale & retail | 2024 |
| Astra Travels Ltd | Administrative & support | 2026 |
| Astral Projects Ltd | Information & communication | 2025 |
| Astralabe Ltd | Construction | 2006 |
| Astralis Care Limited | Health & social care | 2023 |
| Astralis Schools Ltd | Education | 2023 |
| Astraprint UK Ltd | Manufacturing | 2025 |
| Astrarich Ltd | Administrative & support | 1998 |
| Astraveer Ltd | Real estate | 2026 |
| Astria Coffee Solutions Ltd | Other services | 2026 |
| Astro Bowl Limited | Arts & recreation | 2010 |
| Astro Fresh Solutions Ltd | Administrative & support | 2026 |
| Astrobyte Ltd | Professional & scientific | 2023 |
| Astros Trading Ltd | Wholesale & retail | 2022 |
| Astrup Agencies Limited | Arts & recreation | 2002 |
| Astucieux Partners Ltd | Professional & scientific | 2021 |
| Astur Clean Ltd | Administrative & support | 2024 |
| Astute Branding Ltd | Administrative & support | 2020 |
| Astutis Limited | Education | 2010 |
| Astwood Ventures Limited | Real estate | 2013 |
| Astyiel Limited | Wholesale & retail | 2018 |
| ASU Cars Limited | Wholesale & retail | 2015 |
| ASU Services Limited | Professional & scientific | 2023 |
| Asulieman Ltd | Wholesale & retail | 2025 |
| Asuna Ltd | Manufacturing | 2026 |
| ASW Cars Ltd | Wholesale & retail | 2017 |
| ASW Wholesale Ltd | Wholesale & retail | 2015 |
| Aswad Investments Ltd | Wholesale & retail | 2019 |
| Aswani Holdings Limited | Financial services | 2023 |
| ASX Global Ltd | Wholesale & retail | 2025 |
| Asylum and Refugee Care (ARC) Ltd | Education | 2007 |
| Asym Housing Ltd | Real estate | 2023 |
| Asyt Ltd | Education | 2024 |
| ASZ Carz Ltd | Wholesale & retail | 2025 |
| Aszma Property Services Ltd | Real estate | 2024 |
| AT Asset Management Ltd | Real estate | 2022 |
| AT Bridge Fashion Consulting Ltd | Professional & scientific | 2023 |
| AT Building Contractors Ltd | Administrative & support | 2025 |
| AT Car Traders Limited | Wholesale & retail | 2025 |
| AT Education Limited | Education | 2023 |
| AT Energy Solutions Ltd | Administrative & support | 2023 |
| AT Essentials Ltd | Wholesale & retail | 2025 |
| AT Gladstone Ltd | Information & communication | 2017 |
| AT Group Holding Ltd | Professional & scientific | 2020 |
| AT Home Support Limited | Real estate | 2024 |
| AT Home With the Mckenzie's Ltd | Wholesale & retail | 2022 |
| AT Hub Ltd | Wholesale & retail | 2025 |
| AT Land and Property Limited | Real estate | 2010 |
| AT Logistics Solution Ltd | Transport & logistics | 2012 |
| AT One Accountancy Limited | Other services | 2014 |
| AT Pace CIC | Public administration | 2020 |
| AT Peace Care Housing Ltd | Health & social care | 2023 |
| AT Peace Funeral Home Ltd | Other services | 2025 |
| AT Properties Midlands Limited | Real estate | 2019 |
| AT Shoppe Ltd | Wholesale & retail | 2026 |
| AT Surveyors & Builders Limited | Professional & scientific | 2016 |
| AT Thai (Essex) Limited | Hospitality | 2013 |
| AT the Redefined Limited | Other services | 2025 |
| AT Turkish Restaurants Ltd | Hospitality | 2019 |
| AT UK Holdings Limited | Financial services | 2026 |
| AT WOW Price Ltd | Wholesale & retail | 2025 |
| At&S Holdings Limited | Financial services | 2022 |
| At&T Group Limited | Professional & scientific | 2007 |
| At&T Group UK Limited | Professional & scientific | 2015 |
| At-Tarbiyah Ltd | Education | 2025 |
| At-Tariq Accountancy Services Limited | Professional & scientific | 2023 |
| At-Tariq Limited | Real estate | 2004 |
| At.Sw Limited | Wholesale & retail | 2013 |
| AT1 Properties Limited | Real estate | 2023 |
| AT10TION Limited | Wholesale & retail | 2019 |
| AT321 Limited | Real estate | 2025 |
| ATA Enterprises Limited | Administrative & support | 2023 |
| ATA Motors Ltd | Wholesale & retail | 2021 |
| Atablash Ltd | Information & communication | 2012 |
| ATAG80 Limited | Professional & scientific | 2024 |
| Atalanta Group Ltd | Financial services | 2025 |
| Ataraxia Care Services Ltd | Health & social care | 2023 |
| Atayaa Housing Ltd | Hospitality | 2026 |
| ATC Car Service Ltd | Wholesale & retail | 2023 |
| ATC Consultancy Ltd | Other services | 2017 |
| ATC Maintenance Services Ltd | Construction | 2021 |
| ATD Holding Ltd | Other services | 2025 |
| Atec (U.K.) Ltd | Administrative & support | 2017 |
| Ateef Azam Ltd | Health & social care | 2025 |
| Atelier 81 Ltd | Professional & scientific | 2023 |
| Atelier Home and More Ltd | Wholesale & retail | 2025 |
| Atelierluxe Design Ltd | Professional & scientific | 2026 |
| Aterio Technologies Ltd. | Manufacturing | 2021 |
| Atex Industrial Vacuums Ltd | Wholesale & retail | 2016 |
| ATF Screeds Group Limited | Construction | 2025 |
| ATF Screeds Ltd. | Construction | 2014 |
| ATG - IT. Ltd | Information & communication | 1999 |
| ATG Developments Limited | Administrative & support | 2003 |
| ATG Floorings Ltd | Wholesale & retail | 2022 |
| ATH Locum Services Limited | Health & social care | 2003 |
| ATH Outsourcing Limited | Professional & scientific | 2019 |
| Athac CIC | Education | 2013 |
| Athena Business Consultancy Limited | Professional & scientific | 2026 |