Falsehoods Programmers Believe About Phone Numbers

Publisher

Google

URL

https://github.com/google/libphonenumber/blob/master/FALSEHOODS.md

Published

unknown

Updated

unknown

Accessed

2026-09-23

HTTP status

200

License

Apache-2.0 (repository); short excerpts and locators only

Source notes citing this source

• libphonenumber documents that Germany has assigned working numbers longer than the ITU 15-digit maximum. disputed in context
• libphonenumber documents that in Italy the leading zero of a domestically formatted number is part of the number and is kept in international format (for example +39 0…), so stripping a trunk zero is not a universal normalization rule. in context
• ITU-T E.164 limits an international telephone number to at most 15 digits, counting the country code but not the international prefix. in context
• libphonenumber warns against storing phone numbers as numeric types because leading zeros can be significant and part of the number. in context
• libphonenumber documents that the '+' is part of the E.164 format for international numbers and is not optional. in context
• libphonenumber warns that a number that is valid and connects today may be disconnected later, so validity checks are only true at a point in time. in context

Cite this source record

APA

WarmTransfer. (2026, September 23). Falsehoods Programmers Believe About Phone Numbers. WarmTransfer. https://warmtransfer.net/knowledge/sources/gh-google-libphonenumber-falsehoods

BibTeX

@misc{warmtransfer-gh-google-libphonenumber-falsehoods,
  title  = {Falsehoods Programmers Believe About Phone Numbers},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/sources/gh-google-libphonenumber-falsehoods},
  note   = {Google, accessed 2026-09-23}
}