| Accurate Accounts & Tax Ltd | Professional & scientific | 2024 |
| Acda Builders Ltd | Construction | 2022 |
| Acda Property Ltd | Real estate | 2023 |
| Ace and Hammer Limited | Manufacturing | 2019 |
| Ace Development Academy CIC | Education | 2025 |
| Ace Documentation Limited | Information & communication | 2018 |
| Ace Domestic Surrey Ltd | Other services | 2013 |
| Ace Grooming Ltd | Other services | 2019 |
| Ace Learning Academy Ltd. | Professional & scientific | 2013 |
| Ace Learning Centres Limited | Education | 2016 |
| Ace Letting & Refurbishment Ltd | Real estate | 2022 |
| Ace Plan Ltd | Professional & scientific | 2024 |
| Ace Stars Educators Ltd | Education | 2025 |
| Acechange Limited | Information & communication | 2019 |
| Aceline Resources Limited | Professional & scientific | 2003 |
| Acertec Property Solutions Limited | Administrative & support | 2007 |
| Aces Tech Limited | Extraterritorial | 2017 |
| Aces Tech Shop Limited | Construction | 2012 |
| Achalasia Research UK Ltd. | Professional & scientific | 2015 |
| Achill Property Management Ltd | Real estate | 2026 |
| Acme Business Ltd | Real estate | 2021 |
| Acme Investment Limited | Real estate | 2013 |
| Acnj Ltd | Health & social care | 2022 |
| Acorn Lodge Development Ltd | Construction | 2025 |
| Acquacare Services Limited | Health & social care | 2019 |
| Actigas Ltd | Construction | 2022 |
| Acting for Business Limited | Households | 2021 |
| Activ-Air Automation Limited | Wholesale & retail | 1980 |
| Activator Trading Limited | Wholesale & retail | 2024 |
| Active Beauty Limited | Wholesale & retail | 2020 |
| Active TV Aerials Limited | Information & communication | 2009 |
| ACW Building Services Ltd | Construction | 2023 |
| AD DIY Employment Ltd | Administrative & support | 2023 |
| AD Films Ltd | Information & communication | 2020 |
| Ad-Wise World Ltd | Wholesale & retail | 2020 |
| Adam Court Residents Association Limited | Households | 1986 |
| Adamrogersgardens Ltd | Administrative & support | 2026 |
| Adams and Hedges Properties Ltd | Hospitality | 2025 |
| Adamson Berekoff Limited | Other services | 2013 |
| Adaptive Wheels Ltd | Transport & logistics | 2023 |
| ADD a Level Limited | Real estate | 1999 |
| Addington Tyres Ltd | Wholesale & retail | 2013 |
| Aden Estate Ltd | Real estate | 2023 |
| Aden Invest Ltd | Real estate | 2020 |
| Aden Management Ltd | Real estate | 2024 |
| Adenset Trading Ltd | Real estate | 2023 |
| Adhaata Technology Services Ltd | Information & communication | 2017 |
| Aditri Vengal Limited | Health & social care | 2014 |
| Aditya Karra Enterprises Ltd. | Hospitality | 2013 |
| ADK Building Solutions Ltd | Construction | 2015 |
| ADK Property Solutions Ltd | Real estate | 2024 |
| Adland Limited | Professional & scientific | 1999 |
| Admatsim Design Limited | Professional & scientific | 2014 |
| Adolixon & Co. Innovations Ltd | Manufacturing | 2025 |
| Adores Granite Limited | Manufacturing | 2020 |
| Adrian Jackson Consulting Limited | Professional & scientific | 2024 |
| Adrunis Limited | Information & communication | 2013 |
| Adujacq Limited | Health & social care | 2020 |
| ADV2K Ltd | Construction | 2025 |
| Advance Data Analytics Limited | Information & communication | 2024 |
| Advanced Esthetics Solutions Limited | Wholesale & retail | 2010 |
| Advanced GAS SOL Limited | Construction | 2026 |
| Advanced Home Solutions Ltd | Construction | 2025 |
| Advanced Renewable Energies Limited | Construction | 2024 |
| Advanced.R.C Limited | Information & communication | 2025 |
| Advantis Property Group Ltd | Real estate | 2025 |
| Adyan Linen & Laundry Services Ltd | Other services | 2021 |
| Adyan Linen Hire Limited | Other services | 2012 |
| Adyan Textiles (UK) Ltd | Wholesale & retail | 2018 |
| Aegon IT Solutions Limited | Information & communication | 2016 |
| Aegyz Ltd | Financial services | 2026 |
| Ael-Phatha Care Ltd | Health & social care | 2017 |
| Aemo Biotechnology Ltd | Wholesale & retail | 2026 |
| AEO Tech Law Limited | Professional & scientific | 2012 |
| Aerials Satellites and Freeview (UK) Ltd | Administrative & support | 2010 |
| Aeronautical Software Developments Limited | Information & communication | 1996 |
| Aesthetic Materials Ltd | Other services | 2016 |
| AFC Fire and Security Ltd | Professional & scientific | 2005 |
| Affluere Limited | Professional & scientific | 2010 |
| AFH Associates Ltd | Construction | 2025 |
| AFL C&D Ltd | Construction | 2012 |
| Aflex Limited | Information & communication | 1997 |
| AFO Haulage Ltd | Transport & logistics | 2023 |
| Africa Social Project Limited | Education | 2020 |
| Africadigital Group Ltd | Wholesale & retail | 2016 |
| Africhiefs Limited | Manufacturing | 2025 |
| Afropolitan Digital Limited | Information & communication | 2014 |
| Afterglowz Aesthetics and Beauty Limited | Other services | 2025 |
| Afterglowz Limited | Other services | 2023 |
| Afterlive Music Ltd | Information & communication | 2020 |
| Aftershock Total Fitness Limited | Education | 2010 |
| Agaram Publishers Ltd | Information & communication | 2023 |
| Agathletic Limited | Arts & recreation | 2024 |
| AGE UK Sutton | Health & social care | 2001 |
| Agecourrt Limited | Construction | 2024 |
| Agile Projects Europe Ltd | Professional & scientific | 2021 |
| Aglow UK Limited | Real estate | 2020 |
| AGN Maintenance Ltd | Construction | 2022 |
| Agnes & Pavel Ltd | Other services | 2026 |
| AGR Networks Limited | Energy | 2024 |