---
title: Components of a telephone number
description: A telephone number is a unique numerical identifier assigned to a telephone line or device for making and receiving telephone calls. Components of a number are central office code, country code, area code, and rate center.
locale: en-US
canonical_url: https://www.servicenow.com/docs/r/australia/telecom-network-inventory/telecommunications-network-inventory/create\_components.html
release: australia
product: Telecommunications Network Inventory
classification: telecommunications-network-inventory
topic_type: concept
last_updated: "2026-03-12"
reading_time_minutes: 1
breadcrumb: [Telephone allocation, Inventory number allocation, Explore, Telecommunications Network Inventory]
---

# Components of a telephone number

A telephone number is a unique numerical identifier assigned to a telephone line or device for making and receiving telephone calls. Components of a number are central office code, country code, area code, and rate center.

## Central office code, country code, area code, and rate center

-   **Central office code** - The central office code, also known as an exchange code. It identifies a telephone exchange within a particular area code and helps to route calls within the local telephone network. See [Create a central office code](https://raw.githubusercontent.com/ServiceNow/ServiceNowDocs/australia/markdown/australia/telecom-network-inventory/telecommunications-network-inventory/create_a_central_office_code.md) to learn more.
-   **Country code** - A country code is also referred to as an international dialing code. It’s generally a one to three-digit code that is dialed before the area code and telephone number when contacting to another country. See [Create a country code](https://raw.githubusercontent.com/ServiceNow/ServiceNowDocs/australia/markdown/australia/telecom-network-inventory/telecommunications-network-inventory/create_a_country_code.md) to learn more.
-   **Area code** - An area code is a number used to identify a geographic region within a country. See [Create an area code](https://raw.githubusercontent.com/ServiceNow/ServiceNowDocs/australia/markdown/australia/telecom-network-inventory/telecommunications-network-inventory/create_an_area_code.md) to learn more.
-   To learn more about telephone numbers, how to manage and assign them, see [Create a telephone infrastructure](https://raw.githubusercontent.com/ServiceNow/ServiceNowDocs/australia/markdown/australia/telecom-network-inventory/telecommunications-network-inventory/telephone_block_telephone_number_and_telephone_number.md)