| Adrivio Ltd | Transport & logistics | 2022 |
| Adroit Soft Limited | Information & communication | 2017 |
| Adroluc Ltd | Construction | 2018 |
| Adrone Ltd | Professional & scientific | 2023 |
| ADS Echo Media Ltd | Information & communication | 2024 |
| ADS Healthcare Ltd | Health & social care | 2019 |
| ADS Investors Ltd | Real estate | 2024 |
| Adshroy Healthcare Services Limited | Health & social care | 2025 |
| Adstone Consulting Limited | Professional & scientific | 2006 |
| Adugs Beer Limited | Wholesale & retail | 2022 |
| Adugs Foods Limited | Wholesale & retail | 2013 |
| Adur Holdings Ltd | Financial services | 2025 |
| Advance Auto Art Ltd | Wholesale & retail | 2023 |
| Advance Heating and Plumbing Ltd | Construction | 2023 |
| Advance Learning Solution Ltd | Education | 2021 |
| Advance Logistics Support Limited | Administrative & support | 2013 |
| Advance Training Limited | Transport & logistics | 2013 |
| Advanced Dental Prosthetics Limited | Manufacturing | 2017 |
| Advanced Electro-Mechanical Solutions Ltd | Manufacturing | 2007 |
| Advanced Financial Trading Technologies Ltd | Information & communication | 2020 |
| Advanced Living Enterprises Limited | Hospitality | 2017 |
| Advanced Numeracy Transfers UK Limited | Administrative & support | 2011 |
| Advanced Property Management Nottingham Limited | Real estate | 2016 |
| Advanced Roofing Services (Northampton) Limited | Construction | 2018 |
| Advanced Turf Machinery Limited | Other services | 1990 |
| Advanced Vision Technology Limited | Professional & scientific | 1998 |
| Advancing in Property Solutions Limited | Hospitality | 2025 |
| Advantage Connect (NN) Ltd | Administrative & support | 2024 |
| Advantage SG Ltd | Arts & recreation | 2019 |
| Advantage Sport Group CIC | Education | 2021 |
| Advantage Transport and Logistics Limited | Transport & logistics | 2022 |
| Advent Farms Ltd | Agriculture & fishing | 2023 |
| Adventure Automotive UK Limited | Wholesale & retail | 2022 |
| Adventure Geek Travel Ltd | Administrative & support | 2026 |
| Adventure Hounds Ltd | Other services | 2024 |
| Adventure Ways Community Interest Company | Arts & recreation | 2011 |
| Advice for Good CIC | Other services | 2025 |
| Advice Northants C.I.C. | Information & communication | 2025 |
| Adviceair Limited | Administrative & support | 2001 |
| Advocate Group Ltd | Construction | 2018 |
| Advocating Creativity Limited | Education | 2011 |
| ADW Surveying Services Ltd | Construction | 2015 |
| Adweb Digital Limited | Professional & scientific | 2012 |
| Adwick Consulting Limited | Information & communication | 2019 |
| Adwill Company Limited | Professional & scientific | 2012 |
| Adwoa Owusuaa Limited | Health & social care | 2025 |
| ADY Roman Electrical Ltd | Construction | 2019 |
| Adydar Construction Ltd | Construction | 2019 |
| Adymens Furniture Ltd | Manufacturing | 2026 |
| ADYTRANS2018 Ltd | Administrative & support | 2018 |
| Adzepa Limited | Households | 2024 |
| AE 84 Ltd. | Real estate | 2019 |
| AEC (Optics) Ltd | Health & social care | 2022 |
| AEC Real Ltd | Real estate | 2024 |
| Aegis Business Solutions Ltd | Professional & scientific | 2024 |
| Aelin Ltd | Wholesale & retail | 2025 |
| Aenco Limited | Wholesale & retail | 2015 |
| Aeon Nexus - 1.02 Coopers Brow Limited | Real estate | 2024 |
| Aeon Nexus - 30 Sapphire Court Limited | Real estate | 2023 |
| Aeon Nexus - 34 Sapphire Court Limited | Real estate | 2023 |
| Aeon Nexus Group Holdings Ltd | Professional & scientific | 2024 |
| Aeon Nexus Growth Partners Ltd | Financial services | 2024 |
| Aeon Nexus Property Management Ltd | Real estate | 2024 |
| Aeon Sports Nutrition Ltd | Wholesale & retail | 2016 |
| Aerialscans Ltd | Construction | 2025 |
| Aerisfield Ltd | Arts & recreation | 2025 |
| Aerlig Consulting Ltd | Information & communication | 2026 |
| Aero Strategic Consulting Limited | Wholesale & retail | 2025 |
| Aeroclean Energy Ltd | Administrative & support | 2026 |
| Aeropowder Limited | Manufacturing | 2016 |
| AES Group Holdings Limited | Financial services | 2019 |
| AES Storage Ltd | Transport & logistics | 2021 |
| AES Support Services Limited | Manufacturing | 2009 |
| Aesthelis Limited | Financial services | 2018 |
| Aesthetic Dental Laboratory Partnership Ltd | Professional & scientific | 2014 |
| Aesthetic Extra Limited | Wholesale & retail | 2019 |
| Aesthetics by Daniella Ltd | Other services | 2022 |
| Aesthety Ltd | Health & social care | 2020 |
| Aetherion Tech Limited | Wholesale & retail | 2025 |
| Aetiv Carpentry Ltd | Construction | 2023 |
| AEW Investments Limited | Real estate | 2020 |
| AF Simba Limited | Transport & logistics | 2023 |
| Afcomz Ltd | Administrative & support | 2025 |
| Affero Ltd | Administrative & support | 2003 |
| Affinity Day Care C.I.C. | Health & social care | 2020 |
| Affluent Driver Limited | Transport & logistics | 2018 |
| Affluent Ventures Ltd | Health & social care | 2017 |
| Affordable Dreams AD Limited | Wholesale & retail | 2025 |
| AFG Holdings Ltd | Real estate | 2018 |
| Afisco Transit & Removals Ltd | Transport & logistics | 2026 |
| Afiz Amina Ltd | Real estate | 2025 |
| AFM Building Services Limited | Construction | 2016 |
| Africa Alliance Teen Scholarship Ltd | Education | 2016 |
| Africa Alliance Trade Stone Ltd | Transport & logistics | 2016 |
| African Root Ltd | Wholesale & retail | 2021 |
| Afro & Caribbean Superstore Ltd | Wholesale & retail | 2025 |
| Afro Express Mart Limited | Wholesale & retail | 2018 |
| Afro Hub Ltd | Hospitality | 2025 |
| Afro-Pantry & Beyond Ltd | Hospitality | 2025 |
| Afrocenchix Ltd | Administrative & support | 2010 |