| 5S | Sort;Set in Order; Shine; Standardize; Sustain | |
| AAEF | Albanian American Enterprise Fund | |
| AAEI | American Association of Exporters and Importers | |
| AAEN | Asian American Employee Network | |
| AAFES | Army and Air Force Exchange Service | |
| AAIP | Arab Association for Investment Promotion | |
| AAIW | Automotive Aftermarket Industry Week | |
| ABIE | Australian Business in Europe | |
| ABN | Australian Business Number | |
| ABTA | the Asia Business Trade Association | |
| ACBC | Australia China Business Council | |
| ACCC | Australian Competition and Consumer Commission | |
| ACCC | Australian Competition Consumer Commission | |
| ACCeSs | Automated Customs Clearance System | |
| ACCI | Australian Chamber of Commerce and Industry | |
| ACDA | Arms Control and Disarmament Agency | |
| ACE | Automated Commercial Environment | |
| ACE | Advancing Canadian Entrepreneurship | |
| ACEP | Advisory Committee on Export Policy | |
| ACH | Automated Clearing House | |
| ACIO | Australian Commerce and Industry Office | |
| ACMC | Australian Cefact Management Committee | |
| ACN | Australian Company Number | |
| ACOA | Atlantic Canada Opportunities Agency | |
| ACS | Automated Commercial System | |
