Signal & Syntax · Numbers and formats

What Is a Subscriber Number?

The subscriber number (SN) is the last part of a phone number, after the NDC. The SN identifies one line inside the NDC's range.

Also calledSN

Example

+44 20 7946 0000 └── SN

Subscriber Number in Practice

An E.164 number splits into three parts: country calling code, national destination code and subscriber number. The national regulator fixes the length of each part. The NDC and SN together form the national number, dialed after the trunk prefix.

Related Terms

National destination code The national destination code (NDC) follows the country calling code. Country calling code A country calling code is the one-to-three-digit prefix for a country or shared zone. E.164 E.164 is the ITU-T standard for international phone numbers. Numbering plan A numbering plan is the national rulebook for phone numbers.

Read the Guide

Guide

E.164 Phone Number Format Explained

The parts of an international number and how to convert a list. Read the guide →

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