With Meta's WhatsApp username rollout starting August 2026, users who adopt a username will no longer have their phone number included in webhook payloads. Twilio will instead provide the Business-Scoped User ID (BSUID) in a new field called ExternalUserId for all messages. When no phone number is available, Twilio will also put the BSUID in the from field instead of a phone number.

While the BSUID is accessible via Activity.From.Name in Copilot Studio, there is currently no native way to use it for customer identification in D365 Omnichannel. Contact matching relies exclusively on phone numbers, so customers without a visible phone number will result in unmatched conversations.

We request that Microsoft adds native support for BSUID-based contact matching in Omnichannel, and surfaces ExternalUserId as a dedicated context variable in Copilot Studio, so that the BSUID can be stored against contact records and used as a fallback identifier when no phone number is present.

We have already raised this with Microsoft Support and they confirmed that ExternalUserId is not natively surfaced in D365 or Copilot Studio, and that there is no public timeline for native support. Custom workarounds via Power Automate were suggested, but these are not viable as a long-term solution for what will become standard platform behavior.

This is time-sensitive given the August 2026 global rollout deadline.