| Aberwood Ltd | Real estate | 2025 |
| ABG Fabrication Limited | Manufacturing | 2021 |
| ABI Champion PT Ltd | Education | 2025 |
| Abimgold Ltd | Health & social care | 2022 |
| ABL Residential Ltd | Construction | 2021 |
| Ablesure Ltd | Financial services | 2026 |
| Abnprime Limited | Wholesale & retail | 2026 |
| Absnetwork Limited | Administrative & support | 2013 |
| Absolute H Limited | Administrative & support | 2019 |
| Absolute Mobility Limited | Construction | 2009 |
| Absolute Mobility Solutions Ltd | Extraterritorial | 2016 |
| Abubakar Continental Foods Limited | Wholesale & retail | 2021 |
| AC Enterprises Ltd | Administrative & support | 2017 |
| Accelerate Funding Ltd | Information & communication | 2017 |
| Access Law Legal Services Ltd | Professional & scientific | 2024 |
| Access Professionals Limited | Manufacturing | 2005 |
| Acclaims Building Services Limited | Construction | 2012 |
| Acclaims Properties Limited | Real estate | 2025 |
| Account AID Ltd | Professional & scientific | 2024 |
| Accountancy Careers Limited | Extraterritorial | 1981 |
| Accounting Edge Limited | Professional & scientific | 2013 |
| Accounting Futures Ltd | Professional & scientific | 2025 |
| Accounts & Services UN Limited | Professional & scientific | 2012 |
| ACCOUNTS7 Ltd | Administrative & support | 2018 |
| ACD GSE Ltd | Manufacturing | 2015 |
| Ace Property and Landscape Services Ltd | Administrative & support | 2025 |
| Aceprime Solutions Ltd | Administrative & support | 2026 |
| Aceski Limited | Real estate | 2024 |
| Acorn Bearings & Transmission Company Limited | Wholesale & retail | 1988 |
| ACP Plumbing & Heating Ltd | Construction | 2017 |
| Acro Consultancy Ltd | Information & communication | 2025 |
| Acrostine Limited | Information & communication | 2014 |
| Actalent Services Limited | Other services | 2020 |
| Actegy Health Limited | Extraterritorial | 2012 |
| Actegy Limited | Manufacturing | 2003 |
| Active Builders London Ltd | Construction | 2016 |
| Active Nomads Ltd | Hospitality | 2024 |
| ADA Consult Limited | Professional & scientific | 2026 |
| Adahong Consultancy and Management Ltd | Information & communication | 2025 |
| Adam H Solution Ltd | Construction | 2025 |
| Adamson Repairs Ltd | Transport & logistics | 2018 |
| Adapt Ability Limited | Wholesale & retail | 2020 |
| ADB Architectural Design and Planning Ltd | Professional & scientific | 2021 |
| Addixion Limited | Professional & scientific | 2015 |
| Adelski Ltd | Information & communication | 2026 |
| Adepacare+ Ltd | Health & social care | 2026 |
| Adeservices Limited | Transport & logistics | 2025 |
| Adestech Ltd | Information & communication | 2025 |
| Adga Ltd | Other services | 2023 |
| Adgameture Limited | Professional & scientific | 2025 |
| Aditireddy Consulting Limited | Information & communication | 2016 |
| Adiva Limited | Professional & scientific | 2024 |
| Adlr Management Services Limited | Professional & scientific | 2024 |
| ADM4DYN Holding Limited | Administrative & support | 2010 |
| Admire View Limited | Real estate | 2020 |
| Adnan Investment Ltd | Real estate | 2022 |
| Adore Building Services Limited | Construction | 2013 |
| Adovnad Ltd | Extraterritorial | 2022 |
| Adrian’S Stays Ltd | Real estate | 2025 |
| Adrremus Transport Ltd | Administrative & support | 2018 |
| Adshare Holdings Ltd | Construction | 2024 |
| Adult Connections Limited | Wholesale & retail | 2025 |
| Advanced Cooling for Data Centers Ltd | Professional & scientific | 2025 |
| Advanced Door and Gate Automation Ltd | Other services | 2012 |
| Advanced Health Strategies Limited | Health & social care | 2023 |
| Advantage Design and Build Limited | Construction | 2015 |
| Advantage Printroom Ltd | Manufacturing | 2001 |
| Advantek Ltd | Wholesale & retail | 2011 |
| Adved Solutions Limited | Information & communication | 2024 |
| Adviseiq Limited | Information & communication | 2025 |
| AE Holdco Limited | Professional & scientific | 2011 |
| AE Howe Plumbing + Heat Services Ltd | Construction | 2025 |
| Aerospeed 24/7 Ltd | Transport & logistics | 2019 |
| Aesthetics by Samantha Ltd | Other services | 2017 |
| Aestiva Management Limited | Professional & scientific | 2005 |
| Aetherium Air Global Ltd. | Manufacturing | 2023 |
| AF Geotech Engineering Ltd | Construction | 2025 |
| AFC Transport Ltd | Transport & logistics | 2020 |
| Affluxio Ltd | Professional & scientific | 2022 |
| Afharms Ltd | Wholesale & retail | 2020 |
| AFP Reading Limited | Financial services | 2014 |
| Africa Centre NGO Limited | Information & communication | 2018 |
| Africann Holdings Limited | Financial services | 2020 |
| Afrikapu Limited | Wholesale & retail | 2023 |
| Afternoon Tea Collective Ltd | Hospitality | 2025 |
| Afthonia Ltd | Real estate | 2020 |
| Afton Chemical UK Holdings Limited | Financial services | 2010 |
| Afton Chemical UK LLP | | 2014 |
| Against the System Ltd | Wholesale & retail | 2022 |
| AGC Coffee Ltd | Hospitality | 2023 |
| Aggie Properties Ltd | Real estate | 2022 |
| Agile Business Systems Solutions Ltd | Extraterritorial | 2007 |
| Agile Information Management Ltd | Information & communication | 2010 |
| Agility Networks Limited | Information & communication | 1997 |
| AGJ IT Delivery Ltd | Information & communication | 2022 |
| Agmg Ltd | Construction | 2014 |
| Agnew Consulting Limited | Professional & scientific | 2018 |
| Agnieszka S Limited | Health & social care | 2023 |
| Agora Projects Limited | Professional & scientific | 2022 |
| Agosti Limited | Manufacturing | 2019 |