In a tel URI a global number is identified by a leading '+' and must consist of the E.164 country code and national number.

Checked 2026-09-25

Globally unique numbers are identified by the leading '+' character.
Vendor
IETF
Product
tel URI
Subsystem
number format
Deployment
any
Region
not restricted
Release range
RFC 3966
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). Wrong or missing caller ID on outbound calls: source note caller-id-presentation-problems-tel-global-plus. WarmTransfer. https://warmtransfer.net/knowledge/claims/caller-id-presentation-problems-tel-global-plus

BibTeX

@misc{warmtransfer-claim-caller-id-presentation-problems-tel-global-plus,
  title  = {Wrong or missing caller ID on outbound calls: source note caller-id-presentation-problems-tel-global-plus},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/caller-id-presentation-problems-tel-global-plus},
  note   = {Source note caller-id-presentation-problems-tel-global-plus, checked 2026-09-25}
}

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