| Abbreviation | Definition |
|---|---|
| AG | Antigua and Barbuda |
| AGS | Address Guide System |
| AI | Anguilla |
| AIC | Account Identifier Code |
| AL | Albania |
| AM | Activity Model |
| AM | Address Management |
| AMC/F | Airport Mail Center/Facility |
| AMLC | Air Mail Letter Card |
| AMO | Area Maintenance Office |
| AMS | address management services |
| AMS | Aerial Mail Service |
| AMS | Alternate Mailing System |
| AMS-API | Address Matching System Application Programming Interface |
| AN | Netherlands Antilles |
| AO | Angola |
| AO | Associate Post Office |
| AO | Autres Objets (other articles) |
| AOI | Associate Office Infrastructure |
| AP | Accounting Period |