| Addiscott Cheshire Ltd | Arts & recreation | 2026 |
| Addison Group (NW) Ltd | Real estate | 2025 |
| Addison Software Limited | Information & communication | 2021 |
| Addlepool Farm Trading Limited | Professional & scientific | 2020 |
| Address 11 Ltd | Real estate | 2026 |
| Address 12 Limited | Real estate | 2026 |
| Address Investments Churchtown Ltd | Financial services | 2023 |
| Address Properties Limited | Administrative & support | 2012 |
| Addressless Mailing Ltd | Information & communication | 2015 |
| Addvanced Solutions Community Network CIC | Health & social care | 2012 |
| Addvanced Solutions LLP | | 2012 |
| ADE Electrical Contractor's Ltd | Construction | 2021 |
| ADE Fire Secure Ltd | Construction | 2026 |
| ADE UK Holding Limited | Financial services | 2023 |
| Adeel 786 Ltd | Wholesale & retail | 2025 |
| Adefakky Limited | Information & communication | 2020 |
| Adel Builder Services Ltd | Construction | 2026 |
| Adel for Retail Trading Ltd | Wholesale & retail | 2019 |
| Adelaboutique Ltd | Wholesale & retail | 2022 |
| Adelaide Court (2014) Management Company Limited | Households | 2014 |
| Adelaide's Attic Limited | Real estate | 2021 |
| Adelar Estates Limited | Real estate | 2025 |
| Adelar Group Limited | Financial services | 2025 |
| Adeli Gluten Free Ltd | Hospitality | 2025 |
| Adelia Art Gallery Ltd | Wholesale & retail | 2020 |
| Adelphe Properties Limited | Real estate | 2017 |
| Aden Food Store Ltd | Wholesale & retail | 2026 |
| Aden Lina Limited | Hospitality | 2025 |
| Aden Mini Market Ltd | Wholesale & retail | 2025 |
| Aden News Ltd | Wholesale & retail | 2021 |
| Aden Property Limited | Real estate | 2023 |
| Aden Residential Limited | Real estate | 2018 |
| Adenaike Ltd | Arts & recreation | 2025 |
| Adenside Limited | Administrative & support | 2009 |
| Adept Business Management Consultants Limited | Professional & scientific | 2016 |
| Adept Lifestyle Ltd | Other services | 2017 |
| Adept Photography Limited | Professional & scientific | 2013 |
| Adept Unlimited Ltd | Administrative & support | 2023 |
| Adex Care Ltd | Health & social care | 2012 |
| Adex Solutions Ltd | Hospitality | 2009 |
| ADG Technical Services Limited | Professional & scientific | 2014 |
| ADH Audio Visual Ltd | Information & communication | 2019 |
| Adhd Connect CIC | Information & communication | 2023 |
| Adhd Pro Support Ltd | Information & communication | 2025 |
| Adhd Support Services CIC | Education | 2024 |
| Adhdlounge Ltd | Education | 2024 |
| Adhishtam Properties Limited | Real estate | 2025 |
| Adicus Education CIC | Education | 2025 |
| Adikle Construction Ltd Ltd | Manufacturing | 2020 |
| Adisco Convenience Store Limited | Wholesale & retail | 2016 |
| Aditec Engineering Ltd | Professional & scientific | 2025 |
| Aditya Yanuar Limited | Wholesale & retail | 2025 |
| Adiwell Limited | Real estate | 2004 |
| ADJ UK Property Ltd | Real estate | 2025 |
| Adjust Creative Ltd | Information & communication | 2019 |
| ADK Wines Limited | Wholesale & retail | 2023 |
| ADL Estates Ltd | Real estate | 2024 |
| ADL Roofing Distributors Ltd | Wholesale & retail | 2010 |
| Adler Ortho U.K. Limited | Wholesale & retail | 2012 |
| Adley Group Ltd | Health & social care | 2022 |
| Adley Medicals Ltd | Health & social care | 2026 |
| Adlhealthandsafety Ltd | Other services | 2021 |
| Adlib Developments Limited | Real estate | 1997 |
| Adliftly Ltd | Professional & scientific | 2020 |
| Adludio Limited | Information & communication | 2012 |
| ADM Distribution and Trading Limited | Professional & scientific | 2019 |
| ADM Driving Ltd | Education | 2024 |
| ADM Meats Ltd | Wholesale & retail | 2018 |
| ADM Woodcrafts Ltd | Manufacturing | 2013 |
| Admet by Design Limited | Professional & scientific | 2024 |
| Admin 4 U (UK) Limited | Administrative & support | 2008 |
| Adminconsult Limited | Professional & scientific | 2023 |
| Admiral Sports Academy CIC | Education | 2024 |
| Admiral's Signal Ltd | Wholesale & retail | 2025 |
| Admirals Management Company Limited | Households | 2004 |
| ADN Barber Ltd | Other services | 2024 |
| Adnan ALI Groups Limited | Wholesale & retail | 2025 |
| Adnan Hussain MAH Limited | Wholesale & retail | 2026 |
| Adom Healthcare Ltd | Health & social care | 2024 |
| Adon Care Ltd | Health & social care | 2025 |
| Adore Group Ltd | Real estate | 2016 |
| Adoro Estates Limited | Real estate | 2025 |
| Adprop Co (NW) Ltd | Real estate | 2018 |
| ADR Management UK Ltd | Real estate | 2018 |
| ADR Specialists Ltd | Administrative & support | 2021 |
| Adrian Francisco Sanchez Ferrandez Ltd | Administrative & support | 2025 |
| Adrian Transit Ltd | Transport & logistics | 2016 |
| Adrian&Diana Limited | Transport & logistics | 2015 |
| Adrian's Services NW Ltd | Transport & logistics | 2022 |
| Adriana Grigoras Limited | Transport & logistics | 2024 |
| Adrianaalina Ltd | Health & social care | 2017 |
| Adrians Window Cleaning Services Limited | Administrative & support | 2018 |
| Adrift Boats Ltd | Manufacturing | 2024 |
| Adriscom International Products & Services Ltd | Wholesale & retail | 2024 |
| Adrperformance Ltd | Professional & scientific | 2026 |
| Adryan Barber Limited | Other services | 2025 |
| ADS Drainage Ltd | Water & waste | 2026 |
| ADS Savvy Ltd | Information & communication | 2018 |
| Adskinandlaser Ltd | Health & social care | 2026 |
| Adsphere Media Limited | Professional & scientific | 2025 |