| Al-Sky Shisha Ltd | Wholesale & retail | 2020 |
| Alacrity Foundation | Education | 2011 |
| Alan Dixon Auto Repair Services Limited | Wholesale & retail | 2017 |
| Alan Graham Hall Ltd | Professional & scientific | 2025 |
| Alan Thomas Business Limited | Manufacturing | 2013 |
| Alayna Estates Ltd | Real estate | 2025 |
| ALB Property Maintenance U.K Ltd | Construction | 2024 |
| Alban & Yalcin Properties Limited | Real estate | 2025 |
| Albany Chips Ltd | Hospitality | 2024 |
| Albatros Towing Ltd | Transport & logistics | 2013 |
| Albeca Limited | Real estate | 2014 |
| Albert Mews (Newport) Management Limited | Households | 2001 |
| Albert Street Motors Limited | Wholesale & retail | 2023 |
| Albie H Care Limited | Administrative & support | 2018 |
| Albion Electrical Services Ltd | Construction | 2019 |
| Albro Door Systems Limited | Construction | 2002 |
| Alchemy Medicare Limited | Wholesale & retail | 2014 |
| Alchemy Properties LLP | | 2013 |
| Alchemy Qigong Ltd | Health & social care | 2024 |
| Alchemy Systems International Limited | Information & communication | 1998 |
| Alcohol Treatment Wales Limited | Health & social care | 2014 |
| Aldustria (Launceston) Holdings Ltd | Financial services | 2023 |
| Aldustria (Launceston) Ltd | Energy | 2022 |
| Aldustria Ltd | Construction | 2020 |
| Alef Consulting Limited | Information & communication | 2022 |
| Alessandro Pizzeria Ltd | Hospitality | 2022 |
| Aleva Ltd | Professional & scientific | 2023 |
| Alex England Decorators Ltd | Construction | 2018 |
| Alex Figini Creative Limited | Information & communication | 2022 |
| Alexalex Courier Ltd | Transport & logistics | 2025 |
| Alexander's IOW Limited | Other services | 2023 |
| Alexian Freight Services Limited | Transport & logistics | 1998 |
| Alexquintanltd Ltd | Wholesale & retail | 2026 |
| Alexstel Group Limited | Administrative & support | 2023 |
| Alexstel Holdings Limited | Administrative & support | 2023 |
| Alexstel Property Limited | Real estate | 2023 |
| Alextine Catering Limited | Hospitality | 2016 |
| Alfa Technology Ltd | Transport & logistics | 2012 |
| Algernon House Management Limited | Households | 2004 |
| ALI & Akif Car Hire Ltd | Administrative & support | 2021 |
| ALI Auto (NPT) Limited | Wholesale & retail | 2025 |
| ALI Bwanali Limited | Transport & logistics | 2025 |
| ALI H Barber Ltd | Other services | 2021 |
| ALI Khalid Ltd | Wholesale & retail | 2026 |
| Alice Springs Lodge Limited | Hospitality | 2020 |
| Alisea Group Ltd | Information & communication | 2026 |
| Alistair Jones Rural & Development Limited | Real estate | 2000 |
| Alixity Limited | Professional & scientific | 2014 |
| Aliza Brew Limited | Hospitality | 2023 |
| Aljeroudi Locuming Ltd | Health & social care | 2022 |
| Alkana Corporation Limited | Agriculture & fishing | 2015 |
| ALL About the Green Ltd | Other services | 2024 |
| ALL Aspects Cardiff Ltd | Construction | 2022 |
| ALL in 1 MOT Ltd | Wholesale & retail | 2019 |
| ALL Install Limited | Construction | 2023 |
| ALL PS Commerce Ltd | Wholesale & retail | 2023 |
| ALL Round Embroidery Ltd | Manufacturing | 2025 |
| ALL Round Workwear Limited | Manufacturing | 2025 |
| ALL Seasons Property Maintanance Limited | Households | 2024 |
| ALL Sorts N THA Ltd | Administrative & support | 2025 |
| ALL Star Contractors Ltd | Construction | 2017 |
| ALL Things Aesthetics South Wales Ltd | Other services | 2024 |
| ALL Things Rugby Ltd | Manufacturing | 2024 |
| ALL Things SEN Ltd | Education | 2024 |
| ALL World Translations Ltd | Professional & scientific | 2018 |
| Allan,Howdle Medical Ltd | Health & social care | 2019 |
| Allc Property Investment Limited | Real estate | 2022 |
| Allens Food Limited | Hospitality | 2025 |
| Allfather Developments Ltd | Real estate | 2012 |
| Allfit Upvc Installations Limited | Construction | 2021 |
| Alliance Survey & Safety Solutions Ltd | Administrative & support | 2025 |
| Allied Costs Limited | Professional & scientific | 2013 |
| Allmarque PMS Ltd | Construction | 2008 |
| Allmart Trading Limited | Wholesale & retail | 2025 |
| Allsbright Limited | Administrative & support | 2024 |
| Allt-Yr-Yn Lawn Tennis Club Limited | Arts & recreation | 2020 |
| Allwoodink Ltd | Health & social care | 2023 |
| ALM Security Solutions Ltd | Construction | 2019 |
| Almag Limited | Professional & scientific | 2023 |
| Almanso Properties Limited | Real estate | 2017 |
| Almora House Management Company Limited | Households | 2002 |
| Alni&So Limited | Transport & logistics | 2026 |
| ALP Recruitment Group CYF | Administrative & support | 2022 |
| Alpaca Luxury Lodges Ltd | Hospitality | 2022 |
| Alpha (IOW) Ltd. | Transport & logistics | 2003 |
| Alpha Athletic Ltd | Arts & recreation | 2018 |
| Alpha Psychological Consultancy Ltd | Health & social care | 2010 |
| Alpha Quality Care Ltd | Health & social care | 2012 |
| Alphaechosecurity Ltd | Administrative & support | 2025 |
| Alphalec Ltd | Construction | 2025 |
| Alphine Consultants Limited | Professional & scientific | 2016 |
| Alpine Hippy Developments Limited | Real estate | 2021 |
| Alpine Sure Construction Ltd | Construction | 2015 |
| Alrazzaq Professional Services Limited | Information & communication | 2018 |
| ALS Holding Group Services Limited | Financial services | 2021 |
| ALS Human Resources Consulting Ltd | Administrative & support | 2024 |
| ALS Property Rentals Limited | Real estate | 2021 |
| Alsanol Ltd | Other services | 2023 |
| Alsk Holdings Limited | Financial services | 2020 |
| Altair 8 Ltd | Professional & scientific | 2024 |