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E.164 Phone Number Formatter & Validator

Format phone numbers to the ITU-T E.164 standard for APIs (Twilio, AWS SNS). Validate, parse, and convert to international format instantly.

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Category Code Utilities
Type a number. Use international format (+) to auto-detect country.
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E.164 (Strict)
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National Format
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RFC3966 (URI)
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Structure Breakdown 

    

  


        

        
                
        
    


        

            
            
            
        

        

            

                
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About

                
This tool normalizes and validates phone numbers according to the ITU-T E.164 standard, the format required by most telecommunications APIs (Twilio, Nexmo, AWS SNS) and CRM systems. By converting local numbers into a globally unique format, it eliminates routing errors in international communications.
E.164 numbers typically adhere to a strict length limit of 15 digits and must not contain spaces, dashes, or parentheses. The format is critical for ensuring SMS delivery and voice routing across borders.
Note: This tool runs entirely in your browser using a heuristic engine to detect country codes. No data is transmitted to any server, ensuring privacy for your customer lists.

        

                            
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Formulas

                
E.164 = +CC + NDC + SN
Where:
  • CC = Country Code (1-3 digits)
  • NDC = National Destination Code (Area Code)
  • SN = Subscriber Number
Constraint: length(E.164) ≤ 15

            

                            

                
Reference Data

                

                    
ISOCountryPrefix (CC)Sample E.164
USUnited States+1+14155552671
GBUnited Kingdom+44+447911123456
INIndia+91+919876543210
DEGermany+49+4915123456789
AUAustralia+61+61491570006
JPJapan+81+819012345678
CNChina+86+8613800138000
BRBrazil+55+5511987654321
NLNetherlands+31+31612345678
FRFrance+33+33612345678
                

            

            


    
Frequently Asked Questions

    

        
E.164 is the international telephone numbering plan that ensures each device on the PSTN (Public Switched Telephone Network) has a globally unique number. It strictly follows the format: [+] [Country Code] [Subscriber Number] with a maximum of 15 digits.
Validation checks against country-specific rules. Common reasons include: exceeding the 15-digit limit, being too short (incomplete), or containing an invalid country calling code.
The tool includes specific formatting rules for the top 100+ most populated countries. For unsupported regions, it uses a generic fallback that validates based on the standard 15-digit limit.
Yes. Switch to "Bulk Mode" to paste a list of numbers. You can then copy the results or download a cleaned CSV file with the validation status for each number.