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E.164 Format Reference
E.164 Format Rules
Plus Sign Required
Must start with + followed by the country code. No exceptions.
No Formatting
No spaces, dashes, parentheses, or dots. Digits only after the +.
Max 15 Digits
Total number of digits (country code + subscriber number) cannot exceed 15.
Country Code First
The country code (1-3 digits) immediately follows the +. No trunk prefix (0).
How to Validate E.164 Phone Numbers
- 1
Enter your phone number
Type or paste a phone number into the input field. You can enter it in any format: local, national, or international. The tool accepts numbers with or without country codes, dashes, spaces, and parentheses. - 2
Select the default country
Choose the default country from the dropdown menu. This tells the validator which country code to apply when converting local numbers that lack a + prefix. For numbers already in E.164 format, the country is detected automatically. - 3
Review the validation results
The tool instantly shows whether your number is a valid E.164 number. For valid numbers, you get the E.164 output, international and national formats, country code, national number, and number type (mobile, fixed-line, etc.). - 4
Use batch mode for multiple numbers
Switch to Batch Validation mode to validate entire lists at once. Paste one number per line, click Validate All, then copy all valid E.164 numbers with a single click. Ideal for cleaning CRM databases or preparing SMS campaigns.
Common Use Cases
SMS and Voice API Integration
CRM and Database Cleanup
International Customer Verification
Bulk SMS Campaign Preparation
Why Use E.164 Validator?
The E.164 standard, defined by the International Telecommunication Union (ITU-T), is the universal format for representing telephone numbers worldwide. Every valid E.164 number starts with a plus sign followed by up to 15 digits: a country code (1 to 3 digits) and a subscriber number. This tool validates any phone number against the E.164 specification and converts local or national formats into the correct international representation. Whether you are integrating with phone number validation workflows or cleaning data for API consumption, this validator handles it in seconds.
E.164 compliance is not optional for modern communication platforms. Services like Twilio, Amazon SNS, Google Cloud Messaging, and Vonage reject numbers that do not match the standard. Formatting inconsistencies such as parentheses, dashes, spaces, or missing country codes cause silent failures in SMS delivery and voice routing. By validating numbers before they reach your application layer, you eliminate these failures at the source. The batch mode is especially valuable for teams managing large contact lists, letting you paste hundreds of numbers and export only the valid ones. You can also cross-check results with our regex tester if you need custom pattern matching for specific number ranges.
For developers building user registration or verification flows, combining E.164 validation with email validation ensures both primary contact channels are correct before sending confirmation codes. If you handle sensitive customer data, consider running inputs through the data sanitizer to strip unwanted characters before validation. All processing in this tool happens entirely in your browser. No phone numbers are transmitted to any server, making it safe for handling personally identifiable information and compliant with data protection requirements.
How It Compares
Several online E.164 validators exist, but most are server-side tools that transmit your phone numbers to external servers. This raises privacy concerns, especially when validating customer data subject to GDPR, CCPA, or similar regulations. The FindUtils E.164 Validator processes everything client-side in your browser, so no data ever leaves your device. It is completely free with no usage limits and no signup required.
Compared to programmatic libraries like Google's libphonenumber, this tool provides the same validation accuracy through a visual interface that non-developers can use immediately. Developers still benefit from batch processing, one-click export of valid numbers, and instant format conversion, all without writing code or installing dependencies. For teams that need both a quick validation interface and robust API-level checks, this tool covers the first use case while libraries handle the second.