Parse, validate, and format international phone numbers — E.164, international, national, and RFC 3966 tel: URI formats
E.164 is the ITU standard for international phone numbers — a leading +, a country calling code (1–3 digits), and the national subscriber number. Total length must not exceed 15 digits. The national format is how the number is written within its country (often with a leading trunk prefix like 0). The RFC 3966 tel: URI scheme uses E.164 plus optional phone-context. This tool uses a built-in metadata table for 200+ country calling codes and their national trunk prefixes.