| Adrian Air Conditioning Ltd | Construction | 2021 |
| Adrian Birsan Limited | Construction | 2017 |
| Adrian Installations Ltd | Construction | 2025 |
| Adrian Security Ltd | Public administration | 2017 |
| ADS 98 Limited | Financial services | 2021 |
| ADS Accountancy Solutions Ltd | Professional & scientific | 2022 |
| ADS WDC Limited | Health & social care | 2021 |
| Adsan Limited | Administrative & support | 2005 |
| Adsila Limited | Administrative & support | 2012 |
| Adsim Limited | Real estate | 2004 |
| Adspekt Ltd | Wholesale & retail | 2023 |
| ADT Creations Ltd | Construction | 2020 |
| Adts Services Limited | Information & communication | 2020 |
| Advance Maintenance Services Ltd | Extraterritorial | 2007 |
| Advanced Business Consulting Limited | Information & communication | 2021 |
| Advanced Security Group Limited | Administrative & support | 2015 |
| Advancement Book Club Ltd | Information & communication | 2023 |
| Advancive Consultants Limited | Wholesale & retail | 2019 |
| Advantage Equity Limited | Other services | 2022 |
| Advita Limited | Wholesale & retail | 2020 |
| Advvest Limited | Professional & scientific | 2022 |
| ADY Aman Ltd | Information & communication | 2024 |
| ADY Rail Limited | Construction | 2016 |
| Adymar Logistics Ltd | Transport & logistics | 2024 |
| AE Fitting Ltd | Other services | 2018 |
| AEA Construction Group Limited | Construction | 2024 |
| AEC Invest Ltd | Professional & scientific | 2021 |
| Aeoptics Ltd | Wholesale & retail | 2019 |
| AEP Enterprises Limited | Wholesale & retail | 2023 |
| Aerocase Enterprise Limited | Wholesale & retail | 2024 |
| Aesthetic Edge Ltd | Health & social care | 2014 |
| Aesthetics and Holistic Limited | Health & social care | 2024 |
| Aesthetics by DR ANJ Limited | Health & social care | 2020 |
| Aesthetics Limited UK Limited | Wholesale & retail | 2018 |
| Aesthetics World Limited | Wholesale & retail | 2024 |
| Aethra Scent Ltd | Wholesale & retail | 2020 |
| Aevum Bioscience Ltd | Health & social care | 2026 |
| AF Fitted Furniture Ltd | Other services | 2023 |
| AFA Distribution Limited | Wholesale & retail | 2024 |
| Affiliate Vision Ltd | Professional & scientific | 2018 |
| Afflatus Worldwide Limited | Wholesale & retail | 2022 |
| Affluence Clinique Ltd | Other services | 2025 |
| AFG Household & Electronics Ltd | Wholesale & retail | 2023 |
| Afghan Aroma Oxford Ltd | Hospitality | 2025 |
| Afghan Association Paiwand Limited | Education | 2008 |
| Afghan Royale Restaurant Ltd | Hospitality | 2026 |
| AFGHAN24/7 Ltd | Wholesale & retail | 2025 |
| Afghanskills Group Networking UK Ltd | Information & communication | 2025 |
| AFK3 Limited | Real estate | 2021 |
| Africa Telecom Limited | Information & communication | 2017 |
| Africanemigrant Ltd. | Professional & scientific | 2023 |
| Afritrade Limited | Wholesale & retail | 2023 |
| Afrobites Limited | Other services | 2018 |
| Afrobitts Ltd | Information & communication | 2026 |
| Afromm Limited | Professional & scientific | 2016 |
| Afrotise Limited | Wholesale & retail | 2020 |
| AG Capital Partners Ltd | Professional & scientific | 2024 |
| AG Homes & Investments Ltd | Real estate | 2025 |
| AG Lifts Ltd | Construction | 2024 |
| AG NAM Properties Limited | Construction | 2015 |
| Agama Technology Limited | Information & communication | 2024 |
| Agarwal Gupta Holdings Limited | Real estate | 2025 |
| Agency D Ltd | Professional & scientific | 2010 |
| Agentforge Limited | Information & communication | 2026 |
| Agenticise Ltd | Professional & scientific | 2025 |
| Agerium Ltd | Real estate | 2023 |
| Aghili Construction Ltd | Construction | 2021 |
| Agileai Limited | Health & social care | 2019 |
| Agilitas Learning Ltd | Information & communication | 2023 |
| Agipa Limited | Administrative & support | 2009 |
| Agla Investment Ltd | Real estate | 2022 |
| Agni Motorcycles Limited | Manufacturing | 2019 |
| Agni Motors Ltd | Manufacturing | 2021 |
| Agnihotri Consultancy Limited | Information & communication | 1994 |
| AGR Best Plumbing Ltd | Construction | 2019 |
| Agrioleum Trading Ltd | Hospitality | 2024 |
| Agris Group Limited | Real estate | 2015 |
| Agrodel Limited | Construction | 2025 |
| AGS Jointers Ltd | Construction | 2021 |
| Agutter Consulting Services Limited | Professional & scientific | 2023 |
| AH Sunshine Limited | Administrative & support | 2024 |
| AHJ Associates Limited | Professional & scientific | 2011 |
| AHJ Property Limited | Real estate | 2020 |
| AHK Consultancy Limited | Health & social care | 2003 |
| AHK Empire Ltd | Wholesale & retail | 2025 |
| Ahmed Tandoori (Edgware) Limited | Hospitality | 2002 |
| Ahmr Limited | Wholesale & retail | 2025 |
| AI Lighthouse Partners Limited | Professional & scientific | 2025 |
| AI Mobile Tyres Ltd | Wholesale & retail | 2025 |
| AI Seminar Limited | Education | 2025 |
| Aicha Flowers Limited | Wholesale & retail | 2022 |
| AID4STUDENT Ltd | Administrative & support | 2022 |
| Aidat-Shaw (Investments) Ltd | Real estate | 1995 |
| Aidat-Shaw Holdings Ltd | Information & communication | 1989 |
| Aideco Ltd | Wholesale & retail | 2023 |
| Aiden Properties Ltd | Real estate | 2020 |
| AIM Academies Trust | Education | 2002 |
| AIM Advance Limited | Professional & scientific | 2008 |
| AIM and Hope Limited | Extraterritorial | 2026 |
| AIM Medical Ltd | Health & social care | 2010 |