E.164 Phone Number Format

The international phone number format required by the Enrich Layer API for contact lookups.

E.164 is the international telephone numbering standard defined by the ITU-T (International Telecommunication Union). It assigns a globally unique number to every device on the Public Switched Telephone Network (PSTN). This ensures reliable routing of calls and messages across borders.

The Enrich Layer Reverse Contact Number Lookup endpoint requires phone numbers in E.164 format.

Format structure

An E.164 number has three parts: a country code (1–3 digits), an area code, and a subscriber number. The labels below each group show the digit length. Country codes are always 1–3 digits, while area and subscriber lengths vary by country.

E.164 phone number format: plus sign, country code (1–3 digits), area code (variable length), subscriber number (variable length), 15 digits max excluding the plus sign

Begins with a + sign

Only digits after the +

15 digits max (excluding +)

Country codes never start with 0

Examples

E.164 format	Country	Country code	Area code	Subscriber number
`+14155552671`	United States	1	415	5552671
`+442071838750`	United Kingdom	44	20	71838750
`+551155256325`	Brazil	55	11	55256325

Common country codes

Country	Code
United States / Canada	`+1`
United Kingdom	`+44`
Germany	`+49`
France	`+33`
Australia	`+61`
India	`+91`
Brazil	`+55`
Japan	`+81`

Use E.164 with the API

Pass the phone number as a query parameter in E.164 format:

curl \
    -G \
    -H "Authorization: Bearer ${YOUR_API_KEY}" \
    'https://enrichlayer.com/api/v2/reverse_contact_number' \
    --data-urlencode 'phone_number=+14155552671'

Shell

import requests

api_key = 'YOUR_API_KEY'
headers = {'Authorization': 'Bearer ' + api_key}
response = requests.get(
    'https://enrichlayer.com/api/v2/reverse_contact_number',
    params={'phone_number': '+14155552671'},
    headers=headers,
)

Python

Validation tips

Strip all spaces, dashes, and parentheses before sending a number to the API.
Prepend the + and country code if the number is in local format.
Numbers that don't conform to E.164 return a 400 error. See Errors for details.