| AL. Barak Freight and Logistics Limited | Wholesale & retail | 2020 |
| Alan Cooper Cabinetmaker Limited | Manufacturing | 1999 |
| Alan Green Accountancy Limited | Professional & scientific | 2006 |
| Alanod Limited | Manufacturing | 1957 |
| Alastair Kerr Limited | Wholesale & retail | 2002 |
| Alb/On Ltd | Real estate | 2025 |
| Alban Arms & Armour Ltd | Wholesale & retail | 2015 |
| Albion Water Treatment Ltd | Water & waste | 2019 |
| Alcom Enterprises Limited | Information & communication | 2000 |
| Alcutrade Resources Ltd | Wholesale & retail | 2025 |
| Aldcroft Consulting Ltd | Information & communication | 2022 |
| Alder Translations Limited | Professional & scientific | 2021 |
| Aldous Systems (Europe) Limited | Information & communication | 2002 |
| Alecas Medical Limited | Health & social care | 2020 |
| Alemscot Consulting Limited | Transport & logistics | 2017 |
| Alemscot Properties Limited | Real estate | 2020 |
| Alessia Trading Ltd | Administrative & support | 2026 |
| Alex Lungu Limited | Construction | 2024 |
| Alexander Bradley Consulting Limited | Professional & scientific | 2024 |
| Alexis Flooring (Southern) Limited | Extraterritorial | 2014 |
| Alexis Flooring Limited | Construction | 1998 |
| Alexis Subfloor Limited | Construction | 2025 |
| Alfa Curry House Limited | Hospitality | 2018 |
| Alfab Ltd | Manufacturing | 2023 |
| Alfred Tablet Baldinger Ltd | Wholesale & retail | 2026 |
| Algo Bloom Limited | Information & communication | 2020 |
| Algres Limited | Professional & scientific | 2016 |
| Alice Caroline Limited | Administrative & support | 2004 |
| Alice Residential Ltd | Real estate | 2025 |
| Alice@Annaise Delivery Ltd | Transport & logistics | 2026 |
| Alin-Yan Logistics Ltd | Transport & logistics | 2023 |
| Alinesom Services Limited | Construction | 2025 |
| Aliotta Holdings Limited | Financial services | 2003 |
| Aliotta Holdings Service Company Limited | Real estate | 2017 |
| Aliquant and Co Limited | Arts & recreation | 2015 |
| Alison Crabb Marketing & Copywriting Limited | Information & communication | 2013 |
| Alison Foods Limited | Hospitality | 2024 |
| ALL 4 Health Ltd | Wholesale & retail | 2014 |
| ALL About Rose Limited | Wholesale & retail | 2015 |
| ALL Aspect Roofing and Property Services Ltd | Construction | 2025 |
| ALL Axis Enterprises Ltd | Information & communication | 2025 |
| ALL Boxed in Limited | Wholesale & retail | 2013 |
| ALL Day Scaffolding Ltd | Construction | 2022 |
| ALL Fire Services Ltd | Public administration | 2020 |
| ALL Good Stories Limited | Professional & scientific | 2020 |
| ALL Landscaping Ltd | Administrative & support | 2026 |
| ALL Machines Limited | Manufacturing | 2015 |
| ALL Professional Experts Recruitment Ltd | Administrative & support | 2026 |
| ALL Seasons Gardeners Ltd | Construction | 2024 |
| ALL Sparks Electrics Security Services Limited | Construction | 2012 |
| ALL the 4S South Limited | Transport & logistics | 2024 |
| ALL4HEAT Ltd | Construction | 2024 |
| Allen Organ Services Limited | Manufacturing | 2002 |
| Alliance IT Resale Ltd | Wholesale & retail | 2025 |
| Alliance Meditech Limited | Transport & logistics | 2020 |
| Allikas Limited | Financial services | 2016 |
| Allnutt Transport Ltd | Transport & logistics | 2013 |
| Allshapes Cushions Limited | Manufacturing | 1999 |
| Allure Digital Limited | Information & communication | 2025 |
| Allway Connections Limited | Professional & scientific | 1988 |
| ALM Design & Builds Limited | Construction | 2023 |
| Alma Sage Ventures Limited | Administrative & support | 2015 |
| Alma Street Flats Residents RTM Company Limited | Real estate | 2023 |
| Almach Limited | Other services | 2014 |
| Almimo Ltd | Administrative & support | 2015 |
| Almshouse Professional Services Limited | Information & communication | 2024 |
| Alpha 5 Consulting Ltd | Information & communication | 2026 |
| Alpha Beta Management Services Limited | Professional & scientific | 2018 |
| Alpha Plumbing & Maintenance Ltd | Construction | 2016 |
| Alpha Projects Group Limited | Professional & scientific | 2016 |
| Alpha Raptors Limited | Wholesale & retail | 2017 |
| Alpha TRADING23 Limited | Wholesale & retail | 2023 |
| Alpha Verge Limited | Information & communication | 2014 |
| Alphaberry Holding Limited | Financial services | 2024 |
| Alphabet Bidco Limited | Professional & scientific | 2020 |
| Alphamedicol Ltd | Information & communication | 2017 |
| Alphaz Coffee Limited | Hospitality | 2024 |
| Alphaz GR Coffee Ltd | Hospitality | 2025 |
| Alpine Integrated Services Ltd | Administrative & support | 2017 |
| Alpine Journeywise Management Ltd | Hospitality | 2024 |
| Alpine Start Productions Limited | Professional & scientific | 2024 |
| Alpine Support Services Ltd | Administrative & support | 2018 |
| Alquent Limited | Professional & scientific | 2025 |
| Alsultan Sweets Ltd | Manufacturing | 2023 |
| Alt-Av Ltd | Information & communication | 2009 |
| Alta Motors Ltd | Other services | 2023 |
| Altin Scissors Ltd | Other services | 2020 |
| Altok Ltd | Construction | 2024 |
| Alwaani Limited | Wholesale & retail | 2014 |
| Always Gleaming Window Cleaning Limited | Administrative & support | 2024 |
| AM Cloud Limited | Information & communication | 2012 |
| AM11TGX Ltd | Professional & scientific | 2012 |
| Amanah Alliance Limited | Financial services | 2025 |
| Amanie Partners Limited | Professional & scientific | 2020 |
| Amaniya Limited | Wholesale & retail | 2023 |
| Amari Events Hire Ltd | Hospitality | 2019 |
| Amazalo Limited | Wholesale & retail | 2022 |
| Amazing Grace Productions Ltd | Health & social care | 2016 |
| AMB Accounting Ltd | Professional & scientific | 2025 |
| AMB Contracting Limited | Wholesale & retail | 2025 |