| Abbreviation | Definition |
|---|---|
| AAAC | Adopt An African Church |
| AACCC | Ann Arbor Chinese Christian Church |
| AAIF | American Association of Interchurch Families |
| AAOCC | American Apostolic Old Catholic Church |
| ABCIS | American Baptist Churches Information Systems |
| ABLC | Appointed Beyond Local Congregation |
| ACAC | Allegheny Center Alliance Church |
| ACAC | Allied Churches of Alamance |
| ACAC | Allied Churches of Alamance County |
| ACAD | Associated Churches Active in Disaster |
| ACCA | Antiochian Catholic Church in America |
| ACCC | Atlanta Chinese Christian Church |
| ACCM | Advisory Council for the Church's Ministry |
| ACCM | Apostolic Christian Church Missions |
| ACCR | Accelerating Catholic Church Reform |
| ACCU | Aquarian Christine Church Universal |
| ACERO | Assyrian Church of the East Relief Organisation |
| ACEST | Aldershot Church of England Services Trust |
| ACGS | Anglican Church Grammar School |
| ACIC | Anglican Church International Communion |