ITU-T E.164 · RFC 3966 tel: · Scan to Call QR Code
Phone Number Formatter
Format raw contact numbers into globally recognized ITU-T E.164 standards, generate RFC 3966 web dialing links, and scan high-resolution QR codes to dial immediately.
+1
Digit count: 10✓ Valid National Length
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Point camera at QR code to dial +14155552671Standardized Output Specifications
ITU-T E.164 (International)
+14155552671
RFC 3966 tel: URI
tel:+14155552671
National / Domestic Format
(415) 555-2671
International Human-Readable
+1 415 555 2671
Telecommunications Standards: E.164 Architecture, NANP & RFC 3966
The ITU-T E.164 Standard Specification
E.164 is the international public telecommunication numbering plan established by the ITU:
- Structure: Comprises a maximum of 15 digits formatted as
+[Country Code][National Destination Code][Subscriber Number]. - No Local Punctuation: E.164 strictly prohibits parentheses, hyphens, spaces, or leading trunk prefixes (e.g., domestic
0). - Twilio & SMS Gateways: Cloud communication APIs mandate E.164 to eliminate routing ambiguity across global carrier interconnects.
RFC 3966 `tel:` URIs in Web Applications
RFC 3966 standardizes uniform resource identifiers for telephone calls across mobile and desktop browsers:
- Anchor Tags: Implementing
<a href="tel:+14155552671">allows smartphones to open the native telephone dialer with a single tap. - Global Uniqueness: Always prefix the tel: scheme with the plus sign and country code so mobile roamers can place calls without dialing local exit codes (like
011).
Why Strip Trunk Codes?
In countries like the UK (+44), Germany (+49), and Australia (+61), domestic calls require dialing a trunk prefix 0 before the area code (e.g., 020 7946 0958). When converting to international E.164, this leading zero must be stripped because the international country code replaces domestic trunk routing (yielding +442079460958).