| Aeropromotion Limited | Professional & scientific | 1999 |
| Aesthetics by T&A Ltd | Other services | 2025 |
| Affordable Roof Repairs Ltd | Construction | 2025 |
| AFK Group Limited | Education | 2017 |
| Afmb Cargo Ltd | Transport & logistics | 2022 |
| AFR Autos Ltd | Wholesale & retail | 2023 |
| AFT Construction Ltd | Real estate | 2024 |
| AFT Management Limited | Professional & scientific | 2003 |
| Agam Consulting Service Ltd | Information & communication | 2019 |
| Agam Courier Services Ltd | Transport & logistics | 2023 |
| AGG MK Ltd | Real estate | 2025 |
| Agility Fuel Solutions UK Limited | Administrative & support | 2020 |
| AGL Contractors Limited | Construction | 2013 |
| Agrawal Art Properties Limited | Real estate | 2022 |
| AH Mobility Solutions Ltd | Transport & logistics | 2026 |
| AH Painting & Decorating Limited | Construction | 2015 |
| Ahimsa Group Limited | Information & communication | 2020 |
| Aimenza Ltd | Wholesale & retail | 2026 |
| Aionic Technologies Ltd | Information & communication | 2025 |
| Airport Coordination Limited | Transport & logistics | 1991 |
| Airport Transfers 24/7 Ltd | Administrative & support | 2025 |
| Airportlink Services Ltd | Transport & logistics | 2013 |
| Airports Bureau Systems Ltd. | Transport & logistics | 1991 |
| AJ Commercial Holdings Ltd | Real estate | 2024 |
| AJ76 Transport Services Ltd | Transport & logistics | 2019 |
| Ajaib Homes Limited | Real estate | 2022 |
| AJB OFF Licence Ltd | Wholesale & retail | 2021 |
| AJV Consultancy (UK) Ltd | Professional & scientific | 2024 |
| AK Tech Ltd | Information & communication | 2011 |
| AK3 Consulting Ltd | Information & communication | 2024 |
| Aknk Property Investment Ltd | Real estate | 2025 |
| Akogi Limited | Real estate | 2023 |
| AKS1920 Limited | Real estate | 2017 |
| Akshara Consulting Limited | Administrative & support | 2016 |
| AL Brickwork and Landscape Gardening Ltd | Construction | 2023 |
| AL CAS Investments Ltd | Financial services | 2017 |
| Al-Daour Medical Limited | Health & social care | 2014 |
| Al-Kentar Limited | Construction | 2023 |
| Al-Tawheed Arabic School Ltd | Education | 2013 |
| Albion Aero Services Ltd | Wholesale & retail | 2019 |
| Alchemy Financial Solutions Limited | Professional & scientific | 2002 |
| Alchemy Professional Editorial Services Ltd | Information & communication | 2024 |
| Alen Global UK Limited | Other services | 2016 |
| Alessi Transport Ltd | Transport & logistics | 2025 |
| Alexander Wang UK Limited | Wholesale & retail | 2012 |
| Alexv Logistics Ltd | Transport & logistics | 2021 |
| Alfa Sophia Plumbing & Heating Ltd | Construction | 2020 |
| Alhilly United Holding Scope OIL & GAS Limited | Manufacturing | 2018 |
| ALL Aspects Ltd | Construction | 2013 |
| ALL Furniture Bespoke Ltd | Construction | 2016 |
| ALL in 1 Motors Ltd | Wholesale & retail | 2019 |
| ALL J'S Consulting Ltd | Professional & scientific | 2022 |
| ALL Metal Recycling Services Ltd | Water & waste | 2024 |
| ALL Mode Forwarding Limited | Transport & logistics | 1993 |
| ALL Online Limited | Manufacturing | 2017 |
| ALL Purpose Improvements Ltd | Construction | 2018 |
| All-Pro Finance Limited | Professional & scientific | 2018 |
| Allaspects 247 Ltd | Construction | 2024 |
| Allgod Limited | Transport & logistics | 2016 |
| Allie Wnuk Consulting Limited | Professional & scientific | 2023 |
| Allwood Ceiling Services Limited | Construction | 2015 |
| Alora Vitality Ltd | Health & social care | 2026 |
| Alpha & Omega Gates Limited | Arts & recreation | 2025 |
| ALS Autosmart Repairs Ltd | Wholesale & retail | 2025 |
| ALS Free Ltd | Transport & logistics | 2019 |
| Altruistic Labs Limited | Information & communication | 2026 |
| Alupac Ltd | Professional & scientific | 2024 |
| Alyssam Aesthetics Limited | Health & social care | 2020 |
| Alza Accounting & Management Solutions Ltd | Professional & scientific | 2012 |
| AM Global Services Ltd | Construction | 2016 |
| AM International Couriers UK Limited | Transport & logistics | 2013 |
| Amazing House Services Ltd | Administrative & support | 2024 |
| Amber-Rtm Holdings Limited | Professional & scientific | 2012 |
| Amber-Tm Ltd | Administrative & support | 2024 |
| Ambrozia NP Ltd | Wholesale & retail | 2025 |
| AMD Private Limited | Information & communication | 2016 |
| Amesbury Abbey Limited | Health & social care | 2011 |
| Ameya Infotech Limited | Information & communication | 2010 |
| Amicable Responsive Mechanical Services Limited | Construction | 2018 |
| Amigos Hounslow Limited | Hospitality | 2025 |
| Amira Property Services Ltd | Real estate | 2024 |
| Amplify Retail Execution Ltd | Administrative & support | 2020 |
| AMV Flooring Ltd | Construction | 2025 |
| AMY Little Ltd | Professional & scientific | 2026 |
| AN06 Properties Limited | Real estate | 2026 |
| Anaami Paras Ltd | Education | 2010 |
| Anaconda Services (UK) Limited | Information & communication | 2022 |
| Anaconda Software (UK) Limited | Information & communication | 2022 |
| Analytical Mindlabs Ltd | Information & communication | 2024 |
| Analyze Limited | Professional & scientific | 2018 |
| Anamullah Sayed Ltd | Hospitality | 2021 |
| Anand Isher Associates Ltd | Real estate | 2021 |
| Anchor Immigration Advisory Ltd | Professional & scientific | 2026 |
| Andrew Miller Customs Consultancy and Advisory Services Ltd | Professional & scientific | 2026 |
| Ankerwycke Candles Ltd | Manufacturing | 2020 |
| Anna Beauticians Limited | Other services | 2023 |
| Annax Auto Traders Ltd | Wholesale & retail | 2026 |
| Anoha Services Ltd | Professional & scientific | 2011 |
| Answer the Public Holdings Ltd | Professional & scientific | 2020 |
| Answer the Public Ltd | Information & communication | 2020 |