| Admine Limited | Professional & scientific | 2023 |
| Adtai Limited | Professional & scientific | 2016 |
| Adtc Property Services Limited | Real estate | 2023 |
| Adult Outreach and Support Ltd | Health & social care | 2014 |
| Adun's Enterprises Limited | Hospitality | 2022 |
| Advance Ultrasound Direct Ltd | Health & social care | 2022 |
| Advanced Capital Solutions Limited | Financial services | 1997 |
| Advances Services Limited | Information & communication | 2024 |
| Advent Property Management Ltd | Real estate | 2020 |
| Advert Resources Ltd | Transport & logistics | 2024 |
| Aerro-M Ltd | Professional & scientific | 2024 |
| AES INT Ltd | Construction | 2019 |
| Afap Ltd | Health & social care | 2022 |
| Affirm Accounting Limited | Professional & scientific | 2018 |
| Affordable Services Limited | Administrative & support | 2019 |
| AFG Services & Supplies Ltd | Professional & scientific | 2025 |
| African Palliative Care Association UK | Health & social care | 2009 |
| AG Building and Maintenance Limited | Construction | 2021 |
| AGA Corporate Broking Limited | Financial services | 2025 |
| Agam Construction Services Ltd | Construction | 2025 |
| Agama Security Ltd | Administrative & support | 2018 |
| AGB Limited | Hospitality | 2021 |
| Agege Bakery Limited | Administrative & support | 2018 |
| Agile Safety Solutions Limited | Administrative & support | 2020 |
| Agilesoft Limited | Information & communication | 2018 |
| Ahava Collection Ltd | Administrative & support | 2013 |
| AI Beauty Spa Limited | Other services | 2025 |
| AIC Delta Limited | Information & communication | 2015 |
| AIC Delta Property Ltd | Real estate | 2023 |
| Aiman Info-Tech Ltd | Information & communication | 2025 |
| Aixcel Ltd | Information & communication | 2024 |
| AJ Super Tutors Ltd | Education | 2025 |
| Aj's Dental Fairies Recruitment Agency Limited | Administrative & support | 2016 |
| AJA Holdings London Ltd | Financial services | 2024 |
| Ajia Consulting Limited | Professional & scientific | 2025 |
| AJK Witters Limited | Financial services | 2026 |
| Ajna Services Limited | Education | 2023 |
| Ajnk Private Ltd | Wholesale & retail | 2026 |
| AJO Rail Planning Ltd | Professional & scientific | 2025 |
| Akaa United Ltd | Wholesale & retail | 2015 |
| Akala Lifestyle Ltd | Information & communication | 2024 |
| Akbar Fresh Meat Limited | Wholesale & retail | 2025 |
| AKC Homes Limited | Real estate | 2025 |
| AKJ Build Limited | Construction | 2024 |
| AKJ Joinery Limited | Construction | 2023 |
| AKL (Bathrooms) Limited | Construction | 2003 |
| Akriti Limited | Real estate | 2025 |
| AL Vicoletto Ltd | Information & communication | 2026 |
| Alastone Consultancy Limited | Professional & scientific | 2024 |
| Alastone Limited | Financial services | 2023 |
| Alastone Property Ltd | Real estate | 2025 |
| Albannach Consulting Ltd | Information & communication | 2008 |
| Albrj Limited | Construction | 2025 |
| Alcam Consultancy Limited | Administrative & support | 2015 |
| Alers Road Estate Residents Society Limited(The) | Households | 1982 |
| Aletta Property Ltd | Real estate | 2025 |
| Aletta Shaw Ltd | Administrative & support | 2000 |
| Alfos Limited | Hospitality | 2025 |
| Algorythm Limited | Information & communication | 2015 |
| Aligasim Enterprises UK. Ltd | Wholesale & retail | 2026 |
| Aligned Technologies UK Ltd. | Information & communication | 2019 |
| Alison Holdings Ltd | Hospitality | 2021 |
| ALL Elements Ltd | Construction | 2026 |
| ALL Kindza Madness Ltd | Information & communication | 2026 |
| ALL Star Cuisine Limited | Hospitality | 2015 |
| ALL Waste Recycling Ltd | Water & waste | 2023 |
| All-In Bookkeeping Limited | Professional & scientific | 2011 |
| Allsparx Electrical Ltd | Construction | 2019 |
| Allvee's Limited | Administrative & support | 2016 |
| Almas Corporation Ltd | Construction | 2018 |
| Almcq Ltd | Financial services | 2024 |
| Alphawave Capital Limited | Information & communication | 2023 |
| Alpine Building Services Limited | Construction | 2019 |
| Altean Technology Limited | Information & communication | 2018 |
| Alvid Furniture Ltd | Construction | 2016 |
| Alvydas & JOB Ltd | Construction | 2021 |
| Always Glisten Cleaning Services Ltd | Administrative & support | 2025 |
| Always Pilot Limited | Information & communication | 2005 |
| Amadils Ltd | Real estate | 2017 |
| Amadils Management Limited | Information & communication | 2023 |
| Amar Living Ltd | Wholesale & retail | 2026 |
| Amarjeet Singh Ltd | Construction | 2026 |
| Amazing Hair Limited | Other services | 2025 |
| Amazing Travels Ltd | Administrative & support | 2025 |
| AMB Engineering Consultancy Limited | Professional & scientific | 2017 |
| Ambrose Associates Taxation Services Limited | Professional & scientific | 2004 |
| Ameak Limited | Real estate | 2024 |
| Ameena Market Ltd | Wholesale & retail | 2026 |
| Amife Property Group Ltd | Real estate | 2026 |
| Amity Partners Limited | Real estate | 2025 |
| Amje Consultancy Limited | Professional & scientific | 2026 |
| Amje Properties Limited | Real estate | 2017 |
| Amritsar Drylining Ltd | Construction | 2025 |
| AN Gold Properties Ltd | Real estate | 2026 |
| AN Mega Mart Ltd | Wholesale & retail | 2025 |
| Anantshree Residency Ltd | Real estate | 2026 |
| Anarhe Limited | Professional & scientific | 2017 |
| Andrew Brown Consultancy Ltd | Professional & scientific | 2018 |
| Andrew J. Robertson Limited | Financial services | 2003 |
| Andrew Stammers Construction Consultancy Ltd | Professional & scientific | 2016 |