In a standard deployment, IM and Presence must run the same release as Unified CM, and a mismatch is not supported. Centralized deployments may mix releases.

Checked 2026-09-25

a release mismatch is not supported
Vendor
Cisco
Product
IM
Subsystem
version compatibility
Deployment
on-premises
Region
not restricted
Release range
Release 15x
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). Planning a Unified CM upgrade: source note cucm-upgrade-planning-imp-release-must-match. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-upgrade-planning-imp-release-must-match

BibTeX

@misc{warmtransfer-claim-cucm-upgrade-planning-imp-release-must-match,
  title  = {Planning a Unified CM upgrade: source note cucm-upgrade-planning-imp-release-must-match},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/cucm-upgrade-planning-imp-release-must-match},
  note   = {Source note cucm-upgrade-planning-imp-release-must-match, checked 2026-09-25}
}

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