| Adilah Design Ltd | Professional & scientific | 2024 |
| Adinsons Limited | Construction | 2014 |
| Adira Mental Health and Wellbeing Services C.I.C. | Health & social care | 2020 |
| Adivan Design Ltd | Manufacturing | 2026 |
| Adjust Ventures CIC | Professional & scientific | 2024 |
| Adjustech UK Limited | Information & communication | 2024 |
| Adkd Investment Limited | Real estate | 2025 |
| ADL Glazing Ltd | Construction | 2023 |
| ADL Smartcare Limited | Wholesale & retail | 2002 |
| Adldeliveries Ltd | Transport & logistics | 2023 |
| Adler Business Services Limited | Real estate | 2021 |
| Adler Property Services Ltd | Real estate | 2024 |
| Adler Training Services Ltd | Education | 2026 |
| Adlington Engineering Services Ltd | Manufacturing | 2022 |
| Adlux Care Limited | Administrative & support | 2022 |
| ADM & Partners Ltd | Professional & scientific | 2025 |
| ADM General Trading Ltd. | Wholesale & retail | 2025 |
| ADM Logistic Ltd | Transport & logistics | 2025 |
| Admin (Waste Removal) Limited | Water & waste | 2024 |
| Adminglade Limited | Manufacturing | 1983 |
| Admiral House Property Trading Limited | Real estate | 2013 |
| Admirals Properties Limited | Real estate | 2026 |
| Adnan Healthcare Limited | Health & social care | 2020 |
| Adnans Takeaway Limited | Hospitality | 2022 |
| Adolph Sham Limited | Transport & logistics | 2025 |
| Adomis Group Limited | Financial services | 2024 |
| Adonay Group Limited | Health & social care | 2023 |
| Adorn Cosmetics Limited | Other services | 2017 |
| Adornos Ltd | Manufacturing | 2024 |
| Adotar AI Limited | Professional & scientific | 2025 |
| ADP Events Ltd | Other services | 2018 |
| ADR Legal Resolution Ltd | Professional & scientific | 2017 |
| Adrad Commercial Holdings Ltd | Financial services | 2021 |
| Adrad Facilities Limited | Administrative & support | 2019 |
| Adrad Limited | Administrative & support | 2015 |
| Adrialpe-Media London Limited | Information & communication | 2013 |
| Adrian GHE Transport Limited | Transport & logistics | 2025 |
| Adrian Hopkinson Ltd | Construction | 2016 |
| Adrian Madden Ltd | Extraterritorial | 2025 |
| Adriason IT Solutions Ltd | Information & communication | 2018 |
| Adriatic Blue Ltd | Real estate | 2021 |
| Adriel Supported Living Care Ltd | Health & social care | 2019 |
| ADS Appraisal & Development Services Limited | Professional & scientific | 2018 |
| ADS Homes Ltd | Construction | 2019 |
| ADS Inns Ltd | Hospitality | 2024 |
| Ads-Limathon Limited | Information & communication | 2000 |
| Adscompass International Ltd | Professional & scientific | 2023 |
| Adsd Services Ltd | Administrative & support | 2020 |
| Adswad Ltd | Health & social care | 2012 |
| Adswood Lodge Health Care Limited | Health & social care | 2022 |
| Adthe Partnership Ltd | Hospitality | 2024 |
| Aduad Consulting Limited | Information & communication | 2024 |
| Adult Entertainment Limited | Wholesale & retail | 2020 |
| Advance Clinical Practice Solutions Ltd | Health & social care | 2025 |
| Advance Connect Limited | Professional & scientific | 2018 |
| Advance Electrical Ltd | Construction | 2015 |
| Advance Property Developments | Extraterritorial | 1996 |
| Advance Vehicle Solutions Limited | Wholesale & retail | 2022 |
| Advanced Aesthetics Training Academy Limited | Manufacturing | 2017 |
| Advanced Automation and Assembly Ltd. | Manufacturing | 2012 |
| Advanced Biotech Ltd | Professional & scientific | 2025 |
| Advanced Cladding & Insulation Group Limited | Extraterritorial | 1981 |
| Advanced Developments (Yorkshire) Limited | Construction | 2015 |
| Advanced Ductwork Ltd | Construction | 2011 |
| Advanced Economic Development Ltd | Professional & scientific | 2012 |
| Advanced Engineering Techniques Limited | Manufacturing | 1989 |
| Advanced Fire & Security Services Limited | Manufacturing | 1996 |
| Advanced Fluid Technologies Ltd | Administrative & support | 2003 |
| Advanced Glazing Solutions Limited | Construction | 2014 |
| Advanced Hospital Solutions Limited | Health & social care | 2018 |
| Advanced Investment Mechanics Ltd | Financial services | 2025 |
| Advanced Lifting Technology Limited | Manufacturing | 2014 |
| Advanced Metal Consultancy Limited | Professional & scientific | 2026 |
| Advanced Metal Recovery Ltd | Water & waste | 2022 |
| Advanced Paint Solutions Limited | Wholesale & retail | 2019 |
| Advanced Paving and Civils Limited | Construction | 2015 |
| Advanced Scaffold Limited | Construction | 2016 |
| Advanced Surface Solutions Ltd | Manufacturing | 2026 |
| Advanced Visualisation Technologies Ltd | Health & social care | 2022 |
| Advanced Window Blinds Limited | Wholesale & retail | 2011 |
| Advancepsychotherapy Ltd. | Professional & scientific | 2016 |
| Advantage Premium Homes Limited | Real estate | 2019 |
| Advantage Print and Promotions Limited | Manufacturing | 2009 |
| Advantage VAT Services Limited | Professional & scientific | 2020 |
| Adventa Business Solutions Limited | Administrative & support | 2023 |
| Adventure Emporium Ltd | Information & communication | 2026 |
| Adventure Fields Ltd | Arts & recreation | 2025 |
| Advertaz Ltd | Information & communication | 2026 |
| Advertex Ltd | Wholesale & retail | 2025 |
| Advik 2016 Ltd | Wholesale & retail | 2017 |
| Advisivox Limited | Information & communication | 2025 |
| Advisory Vista Limited | Information & communication | 2025 |
| Advs Healthcare Ltd | Health & social care | 2024 |
| Advs Property Limited | Real estate | 2025 |
| ADW Couriers Ltd | Transport & logistics | 2021 |
| ADW Medical Solutions Limited | Professional & scientific | 2018 |
| Adwinma Limited | Wholesale & retail | 2004 |
| ADX Environmental Services Ltd | Administrative & support | 2026 |
| ADZ Barbers Limited | Other services | 2024 |
| AE Analytics Ltd | Information & communication | 2024 |