How to Format Phone Numbers in E.164 for Conversion Tracking

E.164 is the international standard phone number format required by all major ad platforms for Enhanced Conversions. If your phone numbers aren’t in E.164 format before SHA-256 hashing, the hashed values won’t match the ad platform’s records — and your phone-based matching will return zero results.

E.164 Format Rules

+[country code][national number]

Rule	Description
Start with +	Always begins with the plus sign
Country code	1-3 digits (1 for US/Canada, 44 for UK, etc.)
No formatting	No spaces, dashes, parentheses, or dots
Digits only	After the +, only digits
Maximum length	15 digits total (including country code)

Common US Number Transformations

Raw Input	E.164 Output	Valid?
(555) 123-4567	+15551234567	✅
555-123-4567	+15551234567	✅
555.123.4567	+15551234567	✅
5551234567	+15551234567	✅
1-555-123-4567	+15551234567	✅
+1 (555) 123-4567	+15551234567	✅
15551234567	+15551234567	✅

Step-by-Step Conversion

Raw:     "(555) 123-4567"
Step 1:  "5551234567"        ← Remove all non-digit characters
Step 2:  "15551234567"       ← Add country code (if 10 digits)
Step 3:  "+15551234567"      ← Add "+" prefix
Step 4:  SHA-256 hash        ← Hash for Enhanced Conversions

Code Implementation

JavaScript

function toE164(phone, countryCode = '1') {
  // Remove all non-digit characters
  let digits = phone.replace(/\D/g, '');
  
  // Handle US/Canada numbers
  if (countryCode === '1') {
    if (digits.length === 10) {
      return '+1' + digits;
    }
    if (digits.length === 11 && digits.startsWith('1')) {
      return '+' + digits;
    }
  }
  
  // For other countries, prepend country code if needed
  if (!digits.startsWith(countryCode)) {
    return '+' + countryCode + digits;
  }
  
  return '+' + digits;
}

Python

import re

def to_e164(phone, country_code='1'):
    digits = re.sub(r'\D', '', phone)
    if country_code == '1':
        if len(digits) == 10:
            return f'+1{digits}'
        if len(digits) == 11 and digits.startswith('1'):
            return f'+{digits}'
    return f'+{digits}'

Use the E.164 Formatter tool for quick, manual verification.

International Formats

Country	Example Raw	E.164
US/Canada	(555) 123-4567	+15551234567
UK	020 7946 0958	+442079460958
Australia	(02) 1234 5678	+61212345678
Germany	030 123456	+4930123456

The Full Pipeline: Normalize → Format → Hash

Raw phone:     "(555) 123-4567"
     ↓
E.164:         "+15551234567"
     ↓
SHA-256:       "d4f5c3b1e72a9f8d..."
     ↓
Send to platform as hashed_phone_number

All three steps are required. Skip any one and matches will fail.

Common Mistakes

Mistake	Hash of	Platform’s Hash of	Match?
No E.164	SHA("5551234567")	SHA("+15551234567")	❌
Missing +	SHA("15551234567")	SHA("+15551234567")	❌
Kept dashes	SHA("555-123-4567")	SHA("+15551234567")	❌
Correct	SHA("+15551234567")	SHA("+15551234567")	✅

How TUOCA Handles Phone Numbers

TUOCA automates the entire pipeline:

1. Raw input — Accepts any common phone format from your data source
2. Country detection — Uses the account’s country setting
3. E.164 normalization — Strips non-digits, adds country code and +
4. SHA-256 hashing — Hashes the normalized E.164 number
5. Platform routing — Sends the hash to the appropriate API field

You provide raw phone numbers in any format. TUOCA handles the rest.