E.164 Format is the international standard for representing phone numbers. It ensures every phone number is unique, globally recognizable, and compatible with modern telecommunications systems.
Most cloud phone systems, VoIP providers, SMS platforms, and APIs require phone numbers in E.164 Format to correctly route calls and messages.
Why Is E.164 Format Important?
E.164 Format provides a consistent way to represent international phone numbers.
Without a standard format, different countries use different dialing rules, making it difficult for communication platforms to identify the correct destination.
By using E.164 Format, businesses can:
- Improve call routing
- Deliver SMS messages reliably
- Prevent formatting errors
- Integrate with communication APIs
- Support international phone numbers
Additionally, many cloud communication platforms automatically validate phone numbers using this standard.
What Does an E.164 Number Look Like?
An E.164 phone number contains:
- A plus sign (+)
- Country code
- National destination number
Example:
| Country | Local Number | E.164 Format |
|---|---|---|
| United States | (415) 555-2671 | +14155552671 |
| United Kingdom | 020 7946 0958 | +442079460958 |
| India | 098765 43210 | +919876543210 |
| Australia | 0412 345 678 | +61412345678 |
Notice that spaces, brackets, and dashes are removed.
E.164 Format Rules
A valid E.164 phone number:
- Begins with a plus sign (+)
- Includes a valid country code
- Contains only numeric digits after the plus sign
- Does not contain spaces
- Does not contain parentheses
- Does not contain hyphens
- Contains a maximum of 15 digits
Following these rules helps ensure compatibility across global telecommunications networks.
When Should You Use E.164 Format?
Most modern communication platforms expect phone numbers in E.164 Format.
Common use cases include:
- Business phone systems
- VoIP providers
- SMS messaging
- WhatsApp Business integrations
- CRM integrations
- Contact center platforms
- Communication APIs
Using a consistent format also simplifies importing contacts and managing customer records.
How to Convert a Number to E.164 Format
Converting a phone number is straightforward.
- Remove spaces and punctuation.
- Remove any leading zero used for domestic dialing.
- Add the correct country code.
- Add the plus sign (+) before the country code.
Example:
Local number:
(415) 555-2671
E.164 Format:
+14155552671
Another example:
Local number:
09876543210
E.164 Format:
+919876543210
Always verify the correct country code before converting a phone number.
Common Formatting Mistakes
Many phone number validation errors occur because of incorrect formatting.
Avoid these common mistakes:
- Including spaces
- Using brackets or parentheses
- Adding hyphens
- Omitting the country code
- Keeping the domestic trunk prefix (such as a leading zero)
Standardizing contact lists before importing them into your communication platform helps prevent these issues.
Does DialNext Use E.164 Format?
Yes. DialNext uses E.164 Format to help ensure accurate call routing, SMS delivery, and API compatibility.
We recommend storing all customer phone numbers in E.164 Format whenever possible, especially when integrating with CRM systems or importing contact lists.
Frequently Asked Questions
Does E.164 Format Include Spaces?
No. E.164 numbers should not contain spaces, brackets, or hyphens.
What Is the Maximum Length of an E.164 Number?
An E.164 phone number can contain up to 15 digits, excluding the plus sign.
Can I Store All Contacts in E.164 Format?
Yes. Many businesses store every phone number in E.164 Format because it simplifies international calling and API integrations.
Is E.164 Format Required for SMS?
Most cloud messaging providers recommend or require E.164 Format to ensure accurate SMS delivery.
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Additional Resources
Learn more about the international telephone numbering standard:
https://www.itu.int/rec/T-REC-E.164
Need Help?
If you have questions about phone number formatting, international calling, or DialNext integrations, contact us at help@dialnext.io.
