# Sender ID types

A Sender ID is the name or phone number displayed as the sender of an SMS
message. The Sender ID type determines what recipients see, whether they can
reply, and which requirements apply in the destination country.

The appearance of a Sender ID may vary by device and messaging application.
The following examples show how each Sender ID type may appear to recipients.

**Alphanumeric**

[![Example message from an Alphanumeric Sender ID.](../../../_images/alphanumeric.webp)](../../../_images/alphanumeric.webp)

**Long-code**

[![Example message from a Long-code Sender ID.](../../../_images/long-code.webp)](../../../_images/long-code.webp)

**Toll-Free**

[![Example message from a Toll-Free Sender ID.](../../../_images/toll-free.webp)](../../../_images/toll-free.webp)

**Carrier**

[![Example message using a Carrier Sender ID.](../../../_images/carrier.webp)](../../../_images/carrier.webp)

## Sender ID type comparison

| Type | Sender ID format | Common uses | Main requirements |
| --- | --- | --- | --- |
| [Alphanumeric](alphanumeric.html) | A brand name containing letters and numbers, such as `MyBrand`. | - Branded one-way notifications - Alerts - Authentication messages | - Sender ID that matches the brand in the business identity - Business identity and address - Business and messaging information required by the destination   countries |
| [Long-code](long-code.html) | A full-length phone number, such as `12025550123`. | - Two-way customer communication - Business notifications sent from a consistent phone number - US A2P messaging using 10DLC registration | - Eligible active DID number with A2P SMS support - Business identity and address - Business and messaging information |
| [Toll-Free](toll-free.html) | A US Toll-Free DID number, such as `18005550123`. | - Customer care - Service notifications - Business messaging using a Toll-Free number | - Eligible active US Toll-Free DID number with A2P SMS support - Business identity and address - Business and messaging information |
| [Carrier](carrier.html) | A dynamic Sender ID selected by the destination carrier according to local network requirements. | - One-way notifications - Alerts - Authentication messages - Messaging to supported Latin American countries | - Business identity and address - Business and messaging information |

## Learn more about Sender ID types

**Alphanumeric**

Present a recognizable business or brand name instead of a phone number.

[Alphanumeric](alphanumeric.html)

**Long-code**

Send A2P SMS from an eligible DID number and support replies where two-way messaging is available.

[Long-code](long-code.html)

**Toll-Free**

Send business messages from an eligible US Toll-Free DID number.

[Toll-Free](toll-free.html)

**Carrier**

Use a dynamic Sender ID that is assigned by the carrier when the message is delivered.

[Carrier](carrier.html)

## Related resources

**How-to guides**

Create and manage Sender ID Verifications in the DIDWW User Panel.

[How-to guides](../how-to-guides/index.html)

**Sender ID Verification reference**

Look up verification fields, types, statuses, and use-case values.

[Sender ID Verification reference](../sender-id-verification-reference.html)

**Compliance content requirements**

Prepare compliant message content, consent flows, and opt-out methods.

[A2P SMS compliance requirements](../compliance-content-requirements.html)

On this page