libphonenumber documents that the '+' is part of the E.164 format for international numbers and is not optional.

Checked 2026-09-23

Vendor
Google
Product
libphonenumber
Subsystem
normalization pitfalls
Deployment
library
Region
not restricted
Release range
master as of 2026-09-23
Checked
2026-09-23

Sources

Cite this note

APA

WarmTransfer. (2026, September 23). E.164 numbering and dial string normalization: source note e164-numbering-plus-not-optional. WarmTransfer. https://warmtransfer.net/knowledge/claims/e164-numbering-plus-not-optional

BibTeX

@misc{warmtransfer-claim-e164-numbering-plus-not-optional,
  title  = {E.164 numbering and dial string normalization: source note e164-numbering-plus-not-optional},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/e164-numbering-plus-not-optional},
  note   = {Source note e164-numbering-plus-not-optional, checked 2026-09-23}
}

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