| Adaptive Code Ltd | Information & communication | 2017 |
| Adaptive E-Learn System (Ades) Ltd | Information & communication | 2013 |
| Adaptmove Services Ltd | Wholesale & retail | 2024 |
| Adar Group Limited | Professional & scientific | 2024 |
| Adaramolapo Collections Ltd | Real estate | 2025 |
| Adastra Pacific Limited | Wholesale & retail | 2012 |
| Adaugo Signature Cuts Limited | Other services | 2025 |
| ADB Education UK Ltd | Education | 2024 |
| Adban Limited | Financial services | 2019 |
| Adboostuk Ltd | Professional & scientific | 2025 |
| ADC Italian Language and Culture Ltd | Wholesale & retail | 2022 |
| ADC Velasco Ltd | Information & communication | 2025 |
| Adcar Outdoors Ltd | Wholesale & retail | 2025 |
| ADD Housing Ltd | Real estate | 2025 |
| ADD People Limited | Information & communication | 2002 |
| Addag Ltd | Health & social care | 2016 |
| Addanki Builders Ltd | Households | 2025 |
| Adder-Vax Limited | Professional & scientific | 2025 |
| Addi-Tec Limited | Wholesale & retail | 2005 |
| Addicted Original Ltd | Wholesale & retail | 2017 |
| Addicted to Jesus Ltd | Administrative & support | 2022 |
| Addiction Suppliers Ltd | Wholesale & retail | 2025 |
| Addingvalue Ltd | Administrative & support | 2010 |
| Addinstown Investments Limited | Extraterritorial | 2021 |
| Addis Car Repair Ltd | Wholesale & retail | 2026 |
| Addison Building Ltd | Construction | 2009 |
| Addison Electrical Contracting Limited | Construction | 2014 |
| Addison Legal Ltd | Professional & scientific | 2022 |
| Addison Lewis Ltd | Professional & scientific | 2021 |
| Addison Plumbing Services Ltd | Construction | 2024 |
| Addison Transport Limited | Transport & logistics | 2018 |
| Addison Travel Limited | Administrative & support | 1992 |
| Additional Construction Services Ltd | Construction | 2013 |
| Addleshaw Goddard (Hong Kong) Limited | Extraterritorial | 2021 |
| Addo Pharma Ltd | Health & social care | 2020 |
| Addr Advisors 1 Limited | Financial services | 2023 |
| Addr Labs Ltd | Financial services | 2024 |
| Addr Portfolio Services Limited | Professional & scientific | 2023 |
| Addr Studio Ltd | Information & communication | 2023 |
| Addr Ventures Ltd | Financial services | 2023 |
| Addsauz Ltd | Hospitality | 2025 |
| Addy Healthcare Limited | Health & social care | 2015 |
| ADE ADE Ventures Limited | Health & social care | 2014 |
| Ade's Touch Ltd | Other services | 2024 |
| Adea Food Services Ltd | Hospitality | 2022 |
| Adebam Care Limited | Health & social care | 2026 |
| Adebayo Adetiba Limited | Health & social care | 2018 |
| Adebe Limited | Construction | 2023 |
| Adebims Limited | Administrative & support | 2019 |
| Adeblux Ltd | Wholesale & retail | 2023 |
| Adebola Services Limited | Health & social care | 2021 |
| Adebolu Limited | Other services | 2019 |
| Adebooks Ltd | Wholesale & retail | 2026 |
| Adecyn Children's Home Ltd | Health & social care | 2010 |
| Adedam Waste & Cleaning Services Ltd | Administrative & support | 2025 |
| Adedayo L. ADE Limited | Health & social care | 2024 |
| Adeeagle Limited | Administrative & support | 2023 |
| Adeeb Ecommerce Ltd | Wholesale & retail | 2026 |
| Adeeb Enterprises Ltd | Wholesale & retail | 2026 |
| Adeebooks Limited | Wholesale & retail | 2026 |
| Adeeg Solutions Limited | Real estate | 2025 |
| Adeel Entrepreneur Ltd | Wholesale & retail | 2025 |
| Adeenakenny Ventures Ltd | Administrative & support | 2024 |
| Adegraf UK Ltd | Administrative & support | 2017 |
| Adekit Global Venture Limited | Transport & logistics | 2021 |
| Adel Ahmed Saleh Alrumaim Trading Ltd | Wholesale & retail | 2026 |
| Adel Aiyan OPC Ltd | Wholesale & retail | 2025 |
| Adel Equipment Management Limited | Manufacturing | 2023 |
| Adelaide Chambers Limited | Professional & scientific | 2026 |
| Adelaide Finco (UK) Ltd | Wholesale & retail | 2022 |
| Adelaide S.P.A. (UK) Ltd | Wholesale & retail | 2006 |
| Adele Catherine Education Limited | Education | 2025 |
| Adele Catherine Global Limited | Education | 2026 |
| Adele's Aesthetics Limited | Other services | 2015 |
| Adelie Services Ltd | Professional & scientific | 2009 |
| Adelina Apartments Ltd | Real estate | 2024 |
| Adeline Search Ltd | Extraterritorial | 2023 |
| Adelivia Cleaning Services Ltd | Administrative & support | 2025 |
| Adelivia Communications Limited | Information & communication | 2024 |
| Adelkos Ltd | Wholesale & retail | 2021 |
| Adelphi Investments (North West) Limited | Financial services | 2026 |
| Adelphi Wharf Phases 2 & 3 RTM Company Ltd | Households | 2024 |
| Adelstone Dental Care Limited | Health & social care | 2008 |
| Adem Tailor Ltd | Wholesale & retail | 2018 |
| Ademaj Properties Limited | Real estate | 2026 |
| Ademer Limited | Information & communication | 2023 |
| Ademi Ltd | Wholesale & retail | 2025 |
| Ademo Care Ltd | Transport & logistics | 2017 |
| Aden for International Trading Ltd | Wholesale & retail | 2026 |
| Adenik Limited | Professional & scientific | 2024 |
| Adeniyi Medical Limited | Health & social care | 2025 |
| Adept Consulting Engineers (Manchester) Limited | Professional & scientific | 2019 |
| Adept Corporate Services Limited | Administrative & support | 2017 |
| Adept Corporate Services Two Limited | Administrative & support | 2017 |
| Adept Executive Consulting Ltd | Education | 2016 |
| Adept Gastroenterologists UK Ltd | Health & social care | 2020 |
| Adept Lettings & Developments Ltd | Real estate | 2020 |
| Adept Medical Reports Limited | Professional & scientific | 2013 |
| Adept Property Repairs & Maintenance Ltd | Construction | 2025 |
| Adept Roofing Limited | Construction | 2004 |