| Affordable Student Accommodation UK Ltd | Construction | 2026 |
| Aflex Security Limited | Public administration | 2017 |
| Afma Holding Ltd | Financial services | 2026 |
| African Innovation and Development Centre CIC | Agriculture & fishing | 2019 |
| African Super Greens Ltd | Manufacturing | 2026 |
| Afrika Products Limited | Manufacturing | 2017 |
| Afro Beauty Ltd | Other services | 2018 |
| Afro Queen Caribbean Hair and Beauty Salon Limited | Other services | 2020 |
| Afrobunch Ltd | Manufacturing | 2026 |
| AFS Electrical Limited | Construction | 2016 |
| AFT Properties London Ltd | Real estate | 2017 |
| AG Best Fire Protection Ltd | Construction | 2014 |
| AG Drive Ltd | Transport & logistics | 2015 |
| AG Tech UK Ltd | Information & communication | 2025 |
| AG Zeus Transport Ltd | Transport & logistics | 2024 |
| AG1 Installations Limited | Construction | 2017 |
| Agam Haulage Ltd | Transport & logistics | 2023 |
| Agape Consultancy Limited | Administrative & support | 2012 |
| Agave Amica Ltd | Wholesale & retail | 2023 |
| Agave Partners Limited | Wholesale & retail | 2018 |
| AGC Insulation Limited | Construction | 2021 |
| AGE Concern Gillingham | Health & social care | 1999 |
| Agenti AI Ltd | Professional & scientific | 2026 |
| Agile FUNDING4U Limited | Financial services | 2024 |
| AGS Technologies Ltd | Information & communication | 2013 |
| Agsm Limited | Manufacturing | 2012 |
| Aguona Romford Ltd | Wholesale & retail | 2023 |
| AH Businesses Limited | Administrative & support | 2010 |
| AHJ LMA Pubco Ltd | Hospitality | 2026 |
| AHJ Power Solutions Limited | Construction | 2012 |
| AHMAD1978 Limited | Health & social care | 2022 |
| Ahotulag Ltd | Wholesale & retail | 2021 |
| AI Estates Limited | Information & communication | 2019 |
| AIM Central Limited | Manufacturing | 2023 |
| AIM GRP UK Ltd | Other services | 2009 |
| Aintree Building Services Ltd | Construction | 2020 |
| Aiox Ltd | Information & communication | 2024 |
| Air Pack Mechanical Ltd | Energy | 2017 |
| Air-Confidence Ltd | Water & waste | 2024 |
| Aishaan Ltd | Hospitality | 2022 |
| Aished Property Investments Limited | Real estate | 2025 |
| Aizahs Kitchen Limited | Hospitality | 2019 |
| Aizodez Consultants Ltd | Administrative & support | 2019 |
| AJ Accounting Limited | Professional & scientific | 2025 |
| AJ Cheema Ltd | Construction | 2025 |
| AJ Fresh Limited | Wholesale & retail | 2018 |
| AJ Sapra Haulage Ltd | Transport & logistics | 2021 |
| AJ Sapra Property Limited | Real estate | 2024 |
| Ajit Homes Limited | Households | 2025 |
| AJJ Trucking Ltd | Administrative & support | 2022 |
| Ajon Cambridge Ltd | Households | 2023 |
| Ajsm Ltd | Information & communication | 2012 |
| Ajush International Trading Ltd | Hospitality | 2025 |
| AJW LD Ltd | Administrative & support | 2012 |
| AK DOT Limited | Health & social care | 2021 |
| AK Electricians Ltd | Manufacturing | 2019 |
| AK FM Services Ltd | Construction | 2024 |
| AK Silverline Enterprises Ltd | Wholesale & retail | 2026 |
| AK Tech Solutions Limited | Wholesale & retail | 2020 |
| Akaal Workforce Ltd | Construction | 2025 |
| Akal Consultants Ltd | Real estate | 2025 |
| Akal Swift Consultants Ltd | Administrative & support | 2012 |
| Akamis Construction Ltd | Construction | 2022 |
| AKB Investments Kent Ltd | Real estate | 2025 |
| AKD Driving School Limited | Education | 2023 |
| Akdos Security Limited | Administrative & support | 2026 |
| AKG Construction Services Ltd | Construction | 2011 |
| Akindat Design and Consultancy Limited | Education | 2022 |
| Akkela Ltd | Real estate | 2026 |
| AKM Engineering Ltd | Administrative & support | 2024 |
| AKO 1 Limited | Hospitality | 2025 |
| Akon Supplies Ltd | Wholesale & retail | 2025 |
| Akorons Limited | Health & social care | 2019 |
| AKS Refurbishment Ltd | Construction | 2017 |
| Aksaraaharan Private Limited | Wholesale & retail | 2026 |
| Akuagodisgood Ltd | Health & social care | 2014 |
| AL (Alternative Living) Ltd | Other services | 2017 |
| AL Buraq Civil Engineering Limited | Professional & scientific | 2014 |
| AL Landscaping & Drainage Ltd | Administrative & support | 2023 |
| AL Waasi Limited | Professional & scientific | 2014 |
| Alan Shoots Ltd | Information & communication | 2022 |
| Alastair Humphreys Ltd | Information & communication | 2017 |
| Alatar Logistics Group Ltd | Transport & logistics | 2022 |
| Albfra Projects Ltd | Construction | 2014 |
| Alce Martwell Ltd | Professional & scientific | 2022 |
| Alder Design & Build Ltd | Real estate | 2017 |
| Alder Design & Lets Ltd | Real estate | 2024 |
| Aldersgate ROW Ltd | Professional & scientific | 2015 |
| Aleks Construction Ltd | Construction | 2012 |
| Alenka Ltd | Wholesale & retail | 2020 |
| Aletheia Academies Trust | Education | 2011 |
| Aleti Limited | Information & communication | 2026 |
| Alex & Darius Ltd | Construction | 2026 |
| Alex B Limited | Transport & logistics | 2017 |
| Alexander Windele Limited | Professional & scientific | 2018 |
| Alexandrov Construction Services Limited | Construction | 2022 |
| Alexandru Nechifor 94 Ltd | Transport & logistics | 2020 |
| Alexia Transport Ltd | Transport & logistics | 2019 |
| Alextiperig Ltd | Transport & logistics | 2018 |
| Algorial Retail Limited | Wholesale & retail | 2020 |