| Advanced Metocean Ltd | Professional & scientific | 2025 |
| Advanced NDT Solutions Limited | Professional & scientific | 2022 |
| Advanced Orthopaedics Ltd | Health & social care | 2025 |
| Advanced Power Installations Ltd | Construction | 2019 |
| Advanced Roller Doors (E.K.) Limited | Manufacturing | 1997 |
| Advanced Rope Access Ltd. | Professional & scientific | 2008 |
| Advanced Sampling Process Instruments Limited | Professional & scientific | 2014 |
| Advanced Sealants Ltd | Construction | 2026 |
| Advanced Signs Ltd. | Manufacturing | 2015 |
| Advanced Sprinkler Installations Ltd | Public administration | 2025 |
| Advanced Tooling & Components Ltd. | Manufacturing | 2010 |
| Advanced Tooling Services Limited | Manufacturing | 1996 |
| Advanced Ways Limited | Construction | 2012 |
| Advanta Direct Ltd | Financial services | 2001 |
| Advanta Foundation | Administrative & support | 2005 |
| Advanta Investments Ltd | Hospitality | 2024 |
| Advanta Risk Ltd | Financial services | 2000 |
| Advanta Wealth Ltd | Financial services | 2012 |
| Advantage Accounting (Scotland) Limited | Professional & scientific | 2009 |
| Advantage Premium Solutions LP | | 2015 |
| Advantage Squared Ltd | Professional & scientific | 2018 |
| Advantage Wealth Management Group Ltd | Financial services | 2024 |
| Advantage Wealth Management Ltd | Financial services | 2013 |
| Advantis Consulting LP | | 2013 |
| Advarian Properties Ltd | Administrative & support | 2003 |
| Advectus Marketing Ltd | Professional & scientific | 2024 |
| Advent Cover Limited | Manufacturing | 1991 |
| Adventis Digital Limited | Information & communication | 2024 |
| Adventure Events Ltd | Arts & recreation | 2022 |
| Adventure Flight Ltd | Administrative & support | 2025 |
| Adventure Medic Ltd | Information & communication | 2013 |
| Adventure Wood Childcare (Denny) Ltd | Education | 2019 |
| Adversity Fitness Limited | Arts & recreation | 2023 |
| Advert Platform LP | | 2017 |
| Advice Direct Scotland Limited | Information & communication | 2001 |
| Advice Infrastructure Ltd | Administrative & support | 2012 |
| Advice Talks Ltd | Information & communication | 2016 |
| Advideo Ltd | Information & communication | 2017 |
| Advisory Seven Ltd | Professional & scientific | 2024 |
| ADW Holdings (Scotland) Limited | Financial services | 2022 |
| ADW Trades Limited | Construction | 2025 |
| Adwg Ltd | Real estate | 2015 |
| ADX Glasgow Ltd | Wholesale & retail | 2014 |
| ADY Property Ltd | Real estate | 2023 |
| Adzd Properties Limited | Real estate | 2024 |
| Adze & Froe Ltd | Manufacturing | 2023 |
| Adzeedeals Limited | Wholesale & retail | 2026 |
| Adzperts Ltd | Professional & scientific | 2026 |
| AE AYE Solutions Ltd | Information & communication | 2026 |
| AE Bains Ltd | Wholesale & retail | 2026 |
| AE Energy Consulting Limited | Education | 2013 |
| AE Fond Kiss Ltd | Wholesale & retail | 2022 |
| AE Invest Limited | Real estate | 2024 |
| Ae&D Consultancy Ltd | Real estate | 2015 |
| AE14 Ltd | Real estate | 2024 |
| AEA Contracts Ltd | Professional & scientific | 2025 |
| Aeacl Limited | Manufacturing | 2021 |
| AEC PA Solutions Ltd | Administrative & support | 2023 |
| Aecr UK Investment I Limited | Administrative & support | 2019 |
| Aedes Limited | Financial services | 1956 |
| Aedge Consulting Ltd | Information & communication | 2022 |
| AEE Commercial Services Ltd | Professional & scientific | 2014 |
| AEE Electrical Ltd | Construction | 2019 |
| AEE Exhibitions Ltd | Construction | 2021 |
| Aefald Embroidery Limited | Other services | 2015 |
| Aegir Technologies Limited | Professional & scientific | 2012 |
| Aegis Commercial Services Ltd | Administrative & support | 2026 |
| Aegis Cyber Defence Security Systems Ltd | Information & communication | 2026 |
| Aegis IT Ltd | Information & communication | 2019 |
| Aegis Juridical Ltd | Professional & scientific | 2026 |
| AEK Family Limited Partnership | | 2025 |
| AEK Fish & Chips Limited | Hospitality | 2024 |
| AEK Management Ltd | Real estate | 2025 |
| Aekw Holdings Ltd | Financial services | 2025 |
| Aelmon. Construction Solutions Ltd. | Professional & scientific | 2015 |
| Aemie Limited | Real estate | 2023 |
| Aemt FOX Ltd | Wholesale & retail | 2023 |
| Aemt Property Ltd | Real estate | 2025 |
| Aeneas Mañas Brodie | Real estate | 2014 |
| Aeoi Consultancy Ltd | Professional & scientific | 2022 |
| Aeolus Vent Ltd | Construction | 2021 |
| AEP (Scotland) Ltd. | Wholesale & retail | 2010 |
| AEP Stores Limited | Real estate | 2019 |
| Aequa Limited | Professional & scientific | 2021 |
| Aerial Consultants Ltd | Administrative & support | 2020 |
| Aerial Digital Ltd | Information & communication | 2014 |
| Aerial Edge Circus School C.I.C. | Arts & recreation | 2015 |
| Aerial Services Scotland Limited | Information & communication | 2006 |
| Aerial Vault Limited | Information & communication | 2016 |
| Aerillia LP | | 2016 |
| Aerius Marine UK Ltd | Manufacturing | 2016 |
| AERO7 Ltd | Construction | 2026 |
| Aeroarc Ltd | Wholesale & retail | 2025 |
| Aeroblue Limited | Extraterritorial | 1998 |
| Aerocom L.P. | | 2016 |
| Aeroga UK Ltd | Health & social care | 2018 |
| Aerolytics Ltd | Professional & scientific | 2025 |
| Aeromar Marketing LP | | 2017 |
| Aeromat Ltd | Manufacturing | 2023 |
| Aeromax Industrial L.P. | | 2016 |