| ADE Power Limited | Administrative & support | 1997 |
| Adept Agency Ltd | Administrative & support | 2018 |
| ADI Utilities Ltd | Construction | 2021 |
| ADJ (Power) Limited | Construction | 2015 |
| ADL Financial Services Ltd | Professional & scientific | 2018 |
| Adlure Ltd | Professional & scientific | 2025 |
| Admacuk Ltd | Transport & logistics | 2026 |
| Adrian Weiner Transport Ltd | Wholesale & retail | 2015 |
| Advance Motor Parts Ltd | Wholesale & retail | 2025 |
| Advanced Digital Surveys Ltd | Real estate | 2024 |
| Advanced Sign Installation Limited | Construction | 2015 |
| Advantis Ltd | Information & communication | 2004 |
| Advanture Limited | Wholesale & retail | 2001 |
| Adwick MOT and Car Care Centre Limited | Wholesale & retail | 2015 |
| AE Pondenmar Ltd | Health & social care | 2021 |
| Aedus Services Limited | Professional & scientific | 2023 |
| AEM Property Solutions Ltd | Real estate | 2016 |
| AEM Solutions Ltd | Construction | 2010 |
| AER Flooring Ltd | Construction | 2019 |
| Aero Maintenance Limited | Manufacturing | 2002 |
| Aesthetics by Emily Ltd | Administrative & support | 2018 |
| Aesthetics by Joanne Ltd | Health & social care | 2023 |
| Aeyebusiness Limited | Information & communication | 2024 |
| Affordable Picks Limited | Wholesale & retail | 2025 |
| Affordable Tool Supplies Ltd | Wholesale & retail | 2016 |
| AG 17 Limited | Wholesale & retail | 2025 |
| Agney Holdings Ltd | Real estate | 2026 |
| Ahluwalia Consulting Ltd | Information & communication | 2019 |
| Aire Letting Ltd | Real estate | 2023 |
| Airvertise Limited | Extraterritorial | 2010 |
| Ajay's Cafe and Deli Limited | Hospitality | 2025 |
| AJB Rectifiers & Controls Ltd | Manufacturing | 2001 |
| Ajdh Group Limited | Hospitality | 2019 |
| AJS Broadcast Consultation Ltd | Professional & scientific | 2020 |
| AJT Trading Limited | Wholesale & retail | 2020 |
| AJZ Group Ltd | Hospitality | 2016 |
| AKM Recycling Limited | Water & waste | 2016 |
| AKS (Safety & Training) Ltd | Professional & scientific | 2010 |
| AL Groundworks Consultancy Ltd | Professional & scientific | 2024 |
| Alambell Limited | Professional & scientific | 2002 |
| Alamo Limited | Information & communication | 2006 |
| Alanmnixon Consulting Ltd | Wholesale & retail | 2010 |
| Albert Dixon Property Limited | Real estate | 2022 |
| Aldrew Limited | Administrative & support | 2015 |
| Alfendex Ltd | Administrative & support | 2017 |
| ALI & Hussain Limited | Health & social care | 2013 |
| Ali's Amigos Ltd | Hospitality | 2025 |
| Alidana Ltd | Wholesale & retail | 2021 |
| Aligned HR Ltd | Administrative & support | 2018 |
| Alinea Interiors Limited | Construction | 2017 |
| Alis Bitz N Pizzas Limited | Hospitality | 2017 |
| Alistair Robertson Ltd | Professional & scientific | 2025 |
| Alken Services Limited | Professional & scientific | 2016 |
| Alkhaldi Healthcare Limited | Health & social care | 2020 |
| ALL Damp Ltd | Construction | 2025 |
| ALL Floors UK Ltd | Wholesale & retail | 2013 |
| ALL in One Concept Ltd | Administrative & support | 2025 |
| Allen Fabrications & Sons Ltd | Manufacturing | 2004 |
| Allout Bathrooms Ltd | Construction | 2025 |
| Allpipe&Valve Ltd | Professional & scientific | 2019 |
| Allyte Associates Ltd | Construction | 2008 |
| ALM Accounts Limited | Professional & scientific | 2022 |
| ALM Payroll Limited | Professional & scientific | 2025 |
| ALN Building Services Ltd | Construction | 2009 |
| Alon Property Limited | Real estate | 2026 |
| Alpaca Punch Ltd | Arts & recreation | 2024 |
| Alston Van Conversions Limited | Wholesale & retail | 2016 |
| ALT Horizon Ltd | Information & communication | 2026 |
| ALW General Haulage Limited | Transport & logistics | 2018 |
| AM Accommodation Services Ltd | Administrative & support | 2021 |
| AM Accommodations Ltd | Hospitality | 2018 |
| AM Caravan Sales Ltd | Wholesale & retail | 2019 |
| Amarna Services Limited | Real estate | 2020 |
| Ambee Homes Limited | Real estate | 2025 |
| AMC Pictures Limited | Information & communication | 2005 |
| Amduma Properties Ltd | Real estate | 2022 |
| AME Facilities Management Ltd | Administrative & support | 2021 |
| AME Group Associates Limited | Administrative & support | 2020 |
| Ameer Holdings Ltd | Financial services | 2024 |
| AMF Global Ltd. | Wholesale & retail | 2023 |
| Amgrove Limited | Professional & scientific | 2018 |
| AMK Ventures Ltd | Professional & scientific | 2014 |
| Amlac Limited | Administrative & support | 2024 |
| Amplify Creator Network Ltd | Professional & scientific | 2025 |
| AMR Consultancy Limited | Administrative & support | 2026 |
| Amyward Property Ltd | Real estate | 2024 |
| Anand Sweets Kitchen Ltd | Hospitality | 2021 |
| Anchored Systems Limited | Construction | 2025 |
| Andrew Lagden Limited | Education | 2010 |
| Andrew Pickering Design Limited | Information & communication | 2012 |
| Andrew Wright Signs Limited | Construction | 2007 |
| Andrews Bargains Ltd | Wholesale & retail | 2020 |
| Andrusyk Blast Cleaning Limited | Construction | 2006 |
| Andrusyk Classic Bikes Limited | Wholesale & retail | 2022 |
| Andy Fish and Chips Limited | Hospitality | 2026 |
| Angel Nails 15 Ltd | Other services | 2023 |
| Angels Finance Management Ltd | Real estate | 2019 |
| Angels Logistics Ltd | Transport & logistics | 2021 |
| ANK Driving Limited | Transport & logistics | 2016 |
| Anns Convenience Store Limited | Wholesale & retail | 2024 |