E.164 number format
E.164 is the international standard, set by the ITU, for writing phone numbers: a plus sign, the country code and the national number without its leading zero, with no spaces and at most 15 digits.
Examples
| Written locally | In E.164 |
|---|---|
| UK: 020 7946 0000 | +442079460000 |
| Germany: 030 123456 | +4930123456 |
| US: (212) 555-0100 | +12125550100 |
To convert a number, drop the national leading zero (where there is one), add the country code and remove spaces and punctuation. Some systems store the number without the plus sign.
Why it matters
Phone systems, carriers and CRMs match numbers exactly. If one system stores "020 7946 0000" and another "+442079460000", calls may not be linked to the right contact or route. Using E.164 everywhere avoids this.
E.164 in phone.systems™
In phone.systems™, numbers from another carrier added through BYOC are entered in E.164 format in the Numbers area. Numbers from DIDWW appear automatically. Consistent international formatting also helps match callers with contacts in your CRM.