| Abbreviation | Definition |
|---|---|
| AIDEA | Alaska Industrial Development Export Authority |
| AIE | Authority to Initiate Eating |
| AKI | Authority Key Identifier |
| AMBD | Authority Monetari Brunei Darussalam |
| AMLA | Anti Money Laundering Authority |
| ANPA | Association of National Park Authorities |
| ANRA | Armenian Nuclear Regulatory Authority |
| ANSA | Afghan National Standards Authority |
| ANUM | Authority Need Urgency and Money |
| APCZMA | Andhra Pradesh Coastal Zone Management Authority |
| APM | Angkatan Pertahanan Awam Malaysia |
| APTA | Ajax Pickering Transit Authority |
| APUA | Adelanto Public Utility Authority |
| APUA | Antigua Public Utilities Authority |
| AQIS | Authority Quality Improvement Services |
| ARLA | Alcohol Regulatory and Licensing Authority |
| ARWA | Appomattox River Water Authority |
| ASADA | Australian Sport Anti Doping Authority |
| ASPA | American Samoa Power Authority |
| ASRA | Alberta Science and Research Authority |