| AK Media Limited | Information & communication | 2007 |
| AK Swiss Ltd | Wholesale & retail | 2024 |
| Ak&P Ltd | Real estate | 2015 |
| Akaal Environmental Health Limited | Professional & scientific | 2013 |
| Akak Properties Limited | Real estate | 2023 |
| Akayyy Limited | Wholesale & retail | 2025 |
| Akhtar Healthcare Limited | Health & social care | 2015 |
| Aki's Fish Bar Limited | Hospitality | 2007 |
| Akmal Ltd | Health & social care | 2023 |
| AKP Company Services Limited | Professional & scientific | 2018 |
| AKP Indemnity Services Limited | Professional & scientific | 2018 |
| Akshar Lettings Ltd | Hospitality | 2022 |
| AKT Management Limited | Professional & scientific | 2020 |
| AL Grey's Cleaning Services Limited | Administrative & support | 2020 |
| AL Safa Restaurants Limited | Hospitality | 2023 |
| Alabaster and Wilson (Legge Lane Properties) Limited | Real estate | 2018 |
| Alani Holdings Ltd | Financial services | 2026 |
| Albatross GT Ltd | Wholesale & retail | 2017 |
| Alder Property Limited | Real estate | 2015 |
| Aldn Construction Ltd | Construction | 2022 |
| Aldridge Construction Engineering Ltd | Construction | 2015 |
| Aldridge Fish Bar (G & G) Ltd | Hospitality | 2026 |
| Aldridge Loft Conversions Limited | Construction | 2016 |
| Aldridge Personal Training Ltd | Arts & recreation | 2019 |
| Aldridge Stainless & Alloys Ltd | Mining & quarrying | 2013 |
| Aldridge Well-Being Limited | Health & social care | 2022 |
| Aleniv Health Limited | Health & social care | 2026 |
| Alex & Sugs Medical Services Limited | Health & social care | 2022 |
| Alex Hairstyles Ltd | Other services | 2016 |
| Alexandra Investment Group Limited | Real estate | 2025 |
| Alexandra Park Lane Business Enterprise Limited | Construction | 2024 |
| Alexandrs Consulting Ltd | Professional & scientific | 2022 |
| Alfa Z Health Ltd | Health & social care | 2019 |
| Alho Aluminium Limited | Manufacturing | 2025 |
| Alhpha Healthcare Limited | Health & social care | 2025 |
| Ali&Benis Ltd | Other services | 2025 |
| Alice Creative Space CIC | Education | 2025 |
| Alijay Transport Ltd | Transport & logistics | 2023 |
| Alimco Fire & Electrical Limited | Public administration | 2021 |
| Alisan Pizza Ltd | Hospitality | 2019 |
| ALK Enterprises Ltd | Health & social care | 2024 |
| ALL Build and Construct Ltd | Construction | 2025 |
| ALL Day Takeaway Ltd | Hospitality | 2023 |
| ALL Mechanical Services (Midlands) Limited | Manufacturing | 2014 |
| ALL Metal Services Limited | Manufacturing | 1974 |
| ALL Seasons Property Ltd | Real estate | 2016 |
| ALL Systems GAS Ltd | Construction | 2020 |
| ALL Things Holdings Limited | Information & communication | 2025 |
| ALL Things Mango Limited | Wholesale & retail | 2024 |
| ALL UK (Services) Limited | Extraterritorial | 2015 |
| ALL UK Limited | Real estate | 2002 |
| Allagi Limited | Professional & scientific | 2019 |
| Allbuyer Limited | Construction | 2007 |
| Allen Legal Ltd | Real estate | 2023 |
| Allen Price Carpentry & Joinery Limited | Construction | 2016 |
| Allen Properties (Lichfield) Limited | Real estate | 1991 |
| Allen Renovations Ltd | Construction | 2018 |
| Alliance Financial Protection Limited | Financial services | 2025 |
| Alliance Innovation Ltd | Professional & scientific | 2023 |
| Alliance Property and Management Limited | Real estate | 2010 |
| Allied Signs Limited | Manufacturing | 1947 |
| Allrounderoutlet Ltd | Wholesale & retail | 2026 |
| Allsafe Heating and Plumbing Limited | Construction | 2017 |
| Allstoreys (NW) Ltd | Real estate | 2021 |
| Allstoreys Capital Investments Ltd | Real estate | 2021 |
| Allstoreys Developments Ltd | Real estate | 2019 |
| Allstoreys Group (Holdings) Ltd | Financial services | 2019 |
| Allstoreys Investments Ltd | Real estate | 2019 |
| Allstoreys Ltd | Real estate | 2018 |
| Allstoreys Property Management Ltd | Real estate | 2019 |
| Alltracker Ltd | Information & communication | 2025 |
| Almourad Limited | Wholesale & retail | 2024 |
| Aloria Limited | Other services | 2021 |
| ALP Wholesale Limited | Wholesale & retail | 2025 |
| Alpha Community Sports C.I.C. | Education | 2024 |
| Alpha Fire Defence Ltd | Construction | 2025 |
| Alpha Ortho Ltd | Health & social care | 2021 |
| Alpha Quantity Surveyors Limited | Professional & scientific | 2019 |
| Alphago Solutions Ltd | Construction | 2026 |
| Alphatrim Limited | Manufacturing | 2021 |
| Alta & Co Trading Limited | Wholesale & retail | 2016 |
| Alta Vista Services Limited | Administrative & support | 2013 |
| Altair Horizons Limited | Professional & scientific | 2025 |
| Alternative Education Ltd | Education | 2023 |
| Alternative Education Solutions Limited | Education | 2023 |
| Altruis Ltd | Real estate | 2025 |
| Altsol Ltd | Information & communication | 2011 |
| Altus Accountants Limited | Professional & scientific | 2020 |
| Alumnor Education Ltd | Education | 2022 |
| Alushi Vending Limited | Wholesale & retail | 2025 |
| Alwin & Alson Healthcare Ltd | Health & social care | 2026 |
| Alèclee Designs Ltd | Professional & scientific | 2025 |
| AM 360 Financial Planning Limited | Financial services | 2022 |
| AM Care Holdings Limited | Financial services | 2023 |
| AM Clack Limited | Professional & scientific | 2012 |
| AM Contract Services Ltd | Construction | 2026 |
| AM Holistic Care Ltd | Administrative & support | 2025 |
| AM Kitchens & Interiors Ltd | Wholesale & retail | 2021 |
| Amaf Enterprises Ltd | Real estate | 2024 |
| Amaf Tech Ltd | Information & communication | 2021 |