| Abbas Uber Eats Limited | Wholesale & retail | 2025 |
| Abbe Labs Ltd | Professional & scientific | 2026 |
| Abbey Bookbinding & Printing Limited | Information & communication | 2014 |
| Abbey Garages (Cardiff) Limited | Wholesale & retail | 1978 |
| Abbey Skincare Ltd | Wholesale & retail | 2025 |
| Abbfabb Grooming Scissors Ltd | Wholesale & retail | 2020 |
| Abbion Fire & Security Systems Limited | Administrative & support | 2005 |
| Abbitech Ltd | Information & communication | 2019 |
| Abbots Mews Management Limited | Households | 1990 |
| Abbots Ride Limited | Transport & logistics | 2019 |
| Abby Lewis Consulting Ltd. | Financial services | 2014 |
| Abby Management Limited | Construction | 2021 |
| Abby Mann Ltd | Wholesale & retail | 2025 |
| ABC (the Bell) Ltd | Hospitality | 2020 |
| ABC Bouncy Castles Ltd | Arts & recreation | 2021 |
| ABC Childcare Services Limited | Health & social care | 2021 |
| ABC Driving Academy Ltd | Education | 2019 |
| ABC Education Culture Exchange Centre Ltd | Professional & scientific | 2012 |
| ABC Market Method LP | | 2021 |
| ABC Myrddin CYF | Arts & recreation | 2024 |
| ABC Parents CIC | Other services | 2023 |
| Abcai Ltd | Wholesale & retail | 2018 |
| Abcbo Limited | Wholesale & retail | 2018 |
| Abcfist Gaints Ltd | Wholesale & retail | 2024 |
| Abcg Solution Ltd | Wholesale & retail | 2018 |
| Abcoding Ltd | Information & communication | 2014 |
| Abcsales Ltd | Wholesale & retail | 2024 |
| ABCX102 Limited | Extraterritorial | 2019 |
| ABCX103 Limited | Extraterritorial | 2019 |
| ABCX104 Limited | Extraterritorial | 2019 |
| ABCX105 Limited | Extraterritorial | 2019 |
| Abdalla Khalil Ltd | Wholesale & retail | 2025 |
| Abdelhamed Laylah Ltd | Wholesale & retail | 2025 |
| Abdelmaboud Ltd | Other services | 2025 |
| Abder Finance Ltd | Administrative & support | 2024 |
| Abdoolla Family Ltd | Real estate | 2025 |
| Abdul & Waheeda Sattar Properties Limited | Real estate | 2024 |
| Abdul AL Ltd | Wholesale & retail | 2025 |
| Abdul Aziz Hakim Ltd | Administrative & support | 2026 |
| Abdul Majid Group of Companies Ltd | Wholesale & retail | 2026 |
| Abdul Muhit Limited | Transport & logistics | 2020 |
| Abdulateef Hurmus Trading Limited | Wholesale & retail | 2025 |
| Abdulelah Ltd | Transport & logistics | 2025 |
| Abdulhabib Akdag Ltd | Wholesale & retail | 2025 |
| Abduljabbar Healthcare Limited | Health & social care | 2023 |
| Abdulkadir NAZ Limited | Wholesale & retail | 2025 |
| Abdullah Enterprises Limited | Wholesale & retail | 2025 |
| Abdullah Mohamdy Ltd | Wholesale & retail | 2025 |
| Abdullah Mutahar Trading Limited | Wholesale & retail | 2025 |
| Abdullah Yari Ltd | Wholesale & retail | 2023 |
| Abdulrehman Group of Company Ltd | Wholesale & retail | 2025 |
| Abdulwasay Ltd | Wholesale & retail | 2026 |
| Abdul`S Poultry Limited | Wholesale & retail | 2003 |
| Abdur Razzak Ltd | Wholesale & retail | 2025 |
| Abdur Rehman Ltd | Wholesale & retail | 2025 |
| ABE Contractors Ltd | Construction | 2019 |
| Abedi Investments (Newport) Limited | Real estate | 2016 |
| Abedi Limited | Construction | 2009 |
| Abedin Distribution Limited | Wholesale & retail | 2023 |
| Abendo Ltd | Health & social care | 2023 |
| Aberdare Catering Ltd | Real estate | 2016 |
| Aberdare Furniture Company Limited | Manufacturing | 1979 |
| Aberedw Energy Park Limited | Energy | 2020 |
| Abergavenny Cleaning Company Ltd | Administrative & support | 2021 |
| Aberion Ltd | Information & communication | 2011 |
| Aberneath Industries Limited | Manufacturing | 1988 |
| ABG Builds Ltd | Real estate | 2019 |
| ABG Holding Ltd | Households | 2020 |
| ABG Industrial Fabrication & SON Limited | Manufacturing | 2025 |
| ABG International General Trading Ltd | Wholesale & retail | 2025 |
| ABG Properties Ltd | Real estate | 2020 |
| Abgndiaye Ltd | Health & social care | 2019 |
| Abhi Superstores Ltd | Wholesale & retail | 2016 |
| Abhijith Driver Agent Limited | Transport & logistics | 2026 |
| Abhita Land Solution Ltd | Mining & quarrying | 2025 |
| ABI Essentials Ltd | Wholesale & retail | 2025 |
| Abic Limited | Administrative & support | 2025 |
| Abidali Retail Ltd | Wholesale & retail | 2024 |
| Abikem Superstores Ltd. | Wholesale & retail | 2023 |
| Abikeolobe African Grocery Store Ltd | Wholesale & retail | 2025 |
| Abilc Ltd | Professional & scientific | 2014 |
| Ability (Cardiff) Limited | Wholesale & retail | 2003 |
| Ability (South UK) Ltd | Construction | 2011 |
| Abis Group UK Limited | Manufacturing | 2017 |
| Abisel Ltd | Wholesale & retail | 2022 |
| Abjā London Limited | Wholesale & retail | 2020 |
| ABK Accounting Services Limited | Professional & scientific | 2015 |
| ABK Consultancy Limited | Information & communication | 2018 |
| Able Consulting Services Limited | Professional & scientific | 1996 |
| Able Contract Electronics Limited | Manufacturing | 2006 |
| Able Escapes Ltd | Real estate | 2025 |
| Able Groundworks Limited | Construction | 2005 |
| Able Insurance Services Limited | Financial services | 1994 |
| Able Mobility Solutions Ltd | Wholesale & retail | 2019 |
| Able Roofing & Construction Limited | Construction | 2003 |
| Able Shopfronts Gill Limited | Construction | 2019 |
| Ablemade Limited | Extraterritorial | 1994 |
| Abloc Health Ltd | Health & social care | 2024 |
| Abluo Ltd | Administrative & support | 2018 |
| ABM Catering for Leisure Limited | Wholesale & retail | 1988 |