AEP caps the number of external audiences that can be activated per destination instance at 20. "External audiences" include audiences ingested via Federated Audience Composition (FAC), custom audience uploads (CSV, API), and Audience Composition outputs sourced from outside the AEP native profile store. The cap is per destination instance — a destination type (e.g., "Google Ads") can have multiple instances, each with its own 20-audience limit.
When this constraint is load-bearing. Organizations using the AEP-as-edge-node pattern (pattern.aep-as-edge-node) that push CDW-computed segments back into AEP for activation via FAC or reverse-ETL uploads will hit this limit. An organization with >20 CDW-computed audience segments targeting a single destination instance must either: (a) partition across multiple destination instances, (b) consolidate audiences upstream, or (c) use AEP-native segmentation for the overflow.
Note: This limit is sourced from the AEP guardrails page updated April 7, 2026. As with the export KB limits, the underlying entitlement may also appear in the AEP Product Description contract (which returned 403 on fetch during the 2026-05-05 web-refresh). Confidence set to 0.88 pending contract-page verification.