Managing Sender Identifiers (Sender IDs)

A Sender Identifier (also referred to as a Sender ID) is the “From” name or mobile telephone number displayed on the recipient’s phone when they receive your SMS message.

To view and manage your Sender Identifiers, sign in to the Web Application and click Sender Ids (Sender Identifiers) in the left sidebar.

---

Types of Sender Identifiers

Rayo SMS supports two types of Sender Identifiers: Alphanumeric Labels and Mobile Telephone Numbers.

1. Alphanumeric Labels

Examples: ROMEO, MY-SHOP, COMPANY.GR

• Maximum length: Up to 11 characters (including spaces).
• Allowed characters: Latin letters (A-Z, a-z), digits (0-9), spaces, dashes (-), underscores (_), and full stops (.).
• Confirmation: Immediately confirmed upon creation (Confirmed) and ready for use right away.

2. Mobile Telephone Numbers

Examples: 306972669700 or +306972669700

• Length: Between 10 and 15 digits (up to 15 digits maximum).
• Confirmation: Requires SMS Confirmation (pending_confirmation) via a 5-digit verification code sent to that mobile number.
• Expiration: Must be confirmed within 15 minutes of creation.

---

Registering an Alphanumeric Sender Identifier

1. Navigate to Sender Ids in the left sidebar and click New Sender Identifier.
2. Enter your desired alphanumeric label (up to 11 characters, using A-Z, a-z, 0-9, spaces, -, _, or .).
3. Submit the form. Alphanumeric identifiers are immediately set to the Confirmed state and activated so you can start sending messages right away.

Important: Destination Country Pre-Registration

Although alphanumeric labels can be immediately used in the majority of cases, depending on the destination country you want to use such a Sender ID for, it may require pre-registration. Your outgoing SMS may leave our platform but then be blocked at the destination network if its Sender ID is not registered. Please contact us with your Sender ID and the country you want to use it for, and we will get back to you about whether it requires registration or not.

---

Registering & Confirming a Mobile Telephone Number

When you register a mobile telephone number as a Sender Identifier, Rayo SMS verifies that you own or control the number before allowing it to be used as a sender.

1. Go to Sender Ids in the left sidebar and create a new Sender Identifier using your mobile number (10 to 15 digits, e.g., 306972669700 or +306972669700).
2. Upon creation, the identifier enters the pending_confirmation (is not confirmed) state, and Rayo SMS immediately sends a 5-digit confirmation code via SMS to that mobile number.
3. Open the Confirm mobile sender id page, enter the 5-digit code, and click Confirm within 15 minutes.
4. Once confirmed, the mobile number transitions to the Confirmed state and is ready for use.

15-Minute Expiration & Single Pending Limit

• If you do not enter the 5-digit confirmation code within 15 minutes, the pending confirmation expires automatically (expired state).
• Only one mobile Sender Identifier can be in the pending_confirmation state at a time. You must either confirm the pending number or wait 15 minutes for it to expire before registering another mobile telephone number.

---

Activating and Deactivating Sender Identifiers

Each Sender Identifier has both a Confirmation status and an Active status, summarized in the Can Be Used? column:

• Only Sender Identifiers that are both Confirmed and Active (Can Be Used? = Yes) appear in the Send Message dropdown in the web composer and are accepted by the HTTP API.
• You can toggle any confirmed Sender Identifier at any time by clicking Deactivate (to hide it from the composer and prevent API usage) or Activate (to re-enable it).

---

Deleting a Sender Identifier

You can permanently delete a Sender Identifier only if it has never been used to send an SMS message.

Why Used Sender IDs Cannot Be Deleted

Once a Sender Identifier has been used to send at least one SMS in the past, it cannot be deleted (It can't be deleted because it has been used for SMS delivery in the past). This restriction ensures the integrity of your historical delivery and audit logs.

If you no longer wish to use a previously used Sender Identifier, click Deactivate instead—this removes it from active dropdowns and blocks new messages from using it while keeping historical records intact.