> For the complete documentation index, see [llms.txt](https://guides.clickatell.com/ussd-user-guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://guides.clickatell.com/ussd-user-guide/getting-started/overview.md).

# Overview

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Only available in Nigeria and South Africa.
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Unstructured Supplementary Service Data (USSD) is a messaging channel that integrates with [Chat Flow](https://clickatell.gitbook.io/flow/overview) (Clickatell's workflow-building platform) to enable high-speed, interactive communication. 

With USSD, customers can interact with remote applications from their mobile devices in real-time, without an internet connection. 

## Using USSD

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USSD is an effective channel for services such as mobile banking and mobile commerce.
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The USSD channel equips businesses to do the following:

* **Self-services**: Allow customers to do service registrations, make service queries, and make reservations.
* **Acquisition services**: Allow customers to sign up for services, and facilitate customer acquisition through campaigns and advertisements.
* **Financial services**: Allow customers to manage bank accounts (e.g., check account balances, change pins, and make payments and transfers), top-up prepaid products, and generate OTPs.
* **Information services**: Send news, weather, or sport updates to customers.

### USSD benefits

**Businesses** get the benefit of:

* Simple, engaging messaging with customers.
* Reaching customers via a low-cost channel.
* Support for a high volume of transactions and throughput.
* Secure interactions, as information is not stored or entered on the customer's mobile device
* Seamless integration with APIs.
* New business opportunities in USSD banking and mobile commerce.

**Customers** get the benefit of:

* Self-service experiences.
* A channel that's affordable and easy to use.
* Secure transactions.
* Access to 24/7 support and time-critical notifications.
* Usage without any internet connection, data, or smartphone.