> ## Documentation Index
> Fetch the complete documentation index at: https://kero.chat/help/llms.txt
> Use this file to discover all available pages before exploring further.

# About SMS Sender IDs

> Learn what an SMS Sender ID is, how it appears to recipients, and why Sender ID requirements vary between countries.

An **SMS Sender ID** identifies who an SMS message is from. It appears in the sender or "from" field when a message is received on a mobile device.

Depending on the country, mobile network and type of messaging, the Sender ID may appear as a **business or brand name**, a **mobile number**, or another number allocated for messaging.

For example, instead of receiving a message from an unfamiliar number, a customer might receive a message from:

> **KERO**\
> Your order has been dispatched and is on its way.

Using a recognisable Sender ID helps customers understand who is contacting them.

## Types of SMS Sender ID

There are two common types of Sender ID.

### Alphanumeric Sender ID

An alphanumeric Sender ID uses letters and numbers to represent the business or brand sending the message.

Examples include:

* `KERO`
* `MYBANK`
* `SHOP123`

Alphanumeric Sender IDs are commonly used for **one-way business messaging**, where customers do not need to reply directly to the message.

> [!NOTE]
>
> Alphanumeric Sender IDs are generally limited to 11 characters, although availability and requirements vary by country and mobile network.

### Numeric Sender ID

A numeric Sender ID uses a telephone number as the sender.

Depending on the country and messaging service, this could be a:

* long number
* short code
* dedicated messaging number

Numeric Sender IDs may support replies where two-way SMS messaging is available.

## Sender IDs are country-specific

Sender ID rules are not the same everywhere.

Some countries allow businesses to use an alphanumeric Sender ID without prior registration. Others require the Sender ID to be registered and approved before messages can be delivered.

There may also be restrictions on:

* permitted Sender ID types
* brand or business verification
* supported characters
* message content
* two-way messaging
* documentation required for registration

> [!WARNING]
>
> Do not assume that a Sender ID that works in one country can be used in another. Sender ID requirements are determined by local regulations and mobile network rules.

## Do I need to register my Sender ID?

That depends on where your messages are being sent.

Use the **SMS Sender ID requirements by country** directory to check whether registration is required for your destination.

[Check Sender ID requirements by country →](https://kero.chat/help/messaging-resources/messaging-directories/sms-sender-id-requirements-by-country.md)

If registration is required, Kero can help you through the registration process.

[Register an SMS Sender ID →](https://kero.chat/help/messaging-resources/sms-resources/register-an-sms-sender-id.md)


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