Migrate production SMS traffic to a short code with AWS End User Messaging

This article provides a comprehensive guide for migrating production SMS traffic from toll-free numbers or 10DLC to short codes using AWS End User Messaging, covering opt-out list migration, keyword configuration, carrier behavior, and validation strategies.

• Export opted-out numbers from existing originator and backfill into new short code's opt-out list to maintain compliance
• Replicate keyword configurations (STOP, HELP, custom keywords) and two-way messaging settings before cutover
• Carriers treat short codes as new senders; carrier-level opt-outs from toll-free/10DLC don't transfer automatically
• Use pool-based or application-layer routing for phased cutover with both originators active during validation window
• Monitor delivery events via CloudWatch Logs configuration set to compare success rates between old and new originators
• Validate opt-out list completeness, keyword responses, inbound routing, and delivery metrics before decommissioning old number
• Clean up by removing old originator from pools, releasing phone numbers, deleting unused campaigns and opt-out lists

Proper migration planning ensures recipients who previously opted out remain protected and all messaging functionality works seamlessly on the new short code from day one.