| Adgasuk Ltd | Construction | 2018 |
| Adhartas Healthcare Advisors Ltd | Professional & scientific | 2015 |
| Adhi Catering Limited | Hospitality | 2025 |
| Adiddo Hospitality Ltd | Hospitality | 2026 |
| Adil Zayani Ltd. | Real estate | 2025 |
| Adina Hair & Beauty Ltd | Other services | 2021 |
| Adinbell Properties Limited | Real estate | 2001 |
| Adisco Investment Ltd | Real estate | 2024 |
| Adisco Locs Stylist Limited | Real estate | 2019 |
| Adison Cars Ltd | Transport & logistics | 2014 |
| Adisur Ltd | Health & social care | 2011 |
| Aditi (UK) Ltd | Other services | 2011 |
| ADJ Catering Limited | Hospitality | 2026 |
| Adjoa's Kitchen Ltd | Hospitality | 2020 |
| ADK Electrical Limited | Construction | 2025 |
| Adklout Ltd | Information & communication | 2025 |
| Adlington Court Residents Company Limited | Households | 2011 |
| Adlon Enterprises UK Limited | Real estate | 2019 |
| ADM Plastering Limited | Construction | 2025 |
| Admil Cars Ltd | Wholesale & retail | 2024 |
| Admin on Demand Ltd | Administrative & support | 2022 |
| Admiral Close (Weybridge) Management Co Limited | Households | 2011 |
| Admiral Court (Long Sutton) Management Company Limited | Households | 2006 |
| Admiral House (Teddington) RTM Company Limited | Households | 2016 |
| Adobe Property Investment Limited | Real estate | 2017 |
| Adomah Holdings LLP | | 2023 |
| Adonai Group Limited | Wholesale & retail | 2026 |
| Adorar Electrics Limited | Construction | 2025 |
| Adrent Limited | Construction | 2022 |
| Adrian Processess Limited | Construction | 2018 |
| Adriana Pro Cleaning Ltd | Administrative & support | 2025 |
| Adrienne Star Design Ltd | Professional & scientific | 2014 |
| Adroit Healthcare Limited | Professional & scientific | 2021 |
| ADS Autos (Croydon) Ltd | Wholesale & retail | 2024 |
| ADS Optical Limited | Wholesale & retail | 2025 |
| ADS Wave Creation Limited | Information & communication | 2025 |
| Adstar Ltd | Real estate | 2024 |
| Adu's Barbers Limited | Other services | 2020 |
| Advait Group Ltd | Real estate | 2025 |
| Advance Agility Ltd | Other services | 2020 |
| Advance College Ltd | Education | 2024 |
| Advance Exclusive Services Ltd | Health & social care | 2024 |
| Advance Healthcare Solutions Ltd | Administrative & support | 2017 |
| Advance Moves C.I.C. | Administrative & support | 2025 |
| Advanced Care 100 Limited | Health & social care | 2018 |
| Advanced Property Solutions (UK) Ltd | Construction | 2013 |
| Advanced Resin Solutions Croydon Limited | Construction | 2021 |
| Advanced Services 101 Limited | Administrative & support | 2025 |
| Advanced Training & Healthcare Services Ltd | Health & social care | 2021 |
| Advantage Human Ltd | Education | 2026 |
| Adventure Sports & Workwear Ltd | Wholesale & retail | 2026 |
| Adventures Barbers Limited | Other services | 2019 |
| Advice Support Knowledge Information | Health & social care | 2012 |
| Advicethroughlife Ltd | Information & communication | 2019 |
| Adwoo Enterprises Ltd | Real estate | 2025 |
| ADY Trans 24/7 Ltd | Transport & logistics | 2020 |
| ADZ Property Group Ltd | Real estate | 2026 |
| AE Capital Managment Ltd | Professional & scientific | 2021 |
| AEA Foods Limited | Hospitality | 2019 |
| Aedilia Limited | Construction | 2026 |
| Aegeco Ltd | Wholesale & retail | 2025 |
| Aeolus Air Quality Consulting Ltd | Professional & scientific | 2020 |
| Aeon Technologies Limited | Information & communication | 2024 |
| Aequitas PD Partners Ltd | Construction | 2025 |
| AER Properties Limited | Real estate | 2021 |
| Aera Coffee House Ltd. | Hospitality | 2023 |
| Aerfen Ltd | Wholesale & retail | 2014 |
| Aerotech International UK Ltd | Manufacturing | 2025 |
| Aesthetic Design Ltd | Wholesale & retail | 2024 |
| Aesthetic Occasions Ltd | Administrative & support | 2026 |
| Aesthetics by Monique Marie Ltd | Other services | 2023 |
| Aestheticsbykyra Ltd | Health & social care | 2025 |
| Aevum Group Ltd | Financial services | 2026 |
| AF DI Carlo Ltd | Administrative & support | 2017 |
| AF Grant Ltd | Construction | 2014 |
| AFA Support Services Limited | Administrative & support | 2023 |
| AFA Supported Living Ltd | Health & social care | 2023 |
| Afaridan Holdings Limited | Administrative & support | 2018 |
| AFB Builders Ltd | Construction | 2019 |
| AFC Food (UK) Limited | Wholesale & retail | 2009 |
| AFD Consultants Ltd | Information & communication | 2022 |
| Afec Engineering Limited | Professional & scientific | 2026 |
| Afees Pent Property Ltd | Real estate | 2024 |
| Affable Digital Ltd | Information & communication | 2013 |
| Affable Therapy Training Ltd | Other services | 2012 |
| Affiniti Digital Media Limited | Information & communication | 2004 |
| Affinity Associates (Flemmings) Limited | Professional & scientific | 2014 |
| Affinity Healthcare Services Ltd | Administrative & support | 2025 |
| Affordable Carpets Limited | Wholesale & retail | 2009 |
| Affordable Glazing Systems Limited | Wholesale & retail | 2016 |
| AFG Foleshill Supermarket Limited | Wholesale & retail | 2017 |
| AFH Accountants & Co (MRC) Ltd | Professional & scientific | 2020 |
| Afifa Trading Ltd | Wholesale & retail | 2018 |
| Afongate Limited | Professional & scientific | 2021 |
| Afriaccess Ltd | Wholesale & retail | 2025 |
| Africa Young Diplomats Forum CIC | Professional & scientific | 2025 |
| Africagri.Ci Ltd | Extraterritorial | 2010 |
| African Fabrics Limited | Households | 2013 |
| African Food Centre Ltd | Wholesale & retail | 2014 |
| African Forest Ltd | Wholesale & retail | 2014 |