Before you can send your first campaign in Monster SMS, you need a Sender ID. It's the number or name that shows up in your customer's inbox when they get a message from you. No Sender ID, no sending.

There are three ways to set one up, and which one you choose depends on what you already have and what you need. This guide covers all three.

What is a Sender ID?

A Sender ID is the number or name that appears in your customer's inbox when they receive a text from your business. It's the first thing they see before they even open the message.

There are two broad types:

• Numeric Sender ID: A real phone number, like +61 412 345 678. Customers can reply directly to this number.
• Alphanumeric Sender ID: A branded name, like "CoolCafe" or "DentalPlus". One-way only, no replies possible.

Why it matters for your business

The Sender ID is your brand's handshake in every message. Here's what's actually at stake:

• Recognition. Customers are far more likely to open a message from a number they recognise or a name they know, compared to a random shortcode they've never seen.
• Trust. In Australia, SMS scams are common. A familiar number or branded name signals legitimacy.
• Replies. If you add a real phone number, customers can reply and you get two-way SMS conversations. With alphanumeric IDs, that's not possible.
• Spam Act compliance. Australia's Spam Act 2003 requires your messages to clearly identify who sent them. A properly registered Sender ID covers this requirement.

Your three options

Option 1: Add your own mobile number

This is the most common setup for small and medium businesses. You add a mobile number you already have, Monster SMS sends a verification code to it, and once confirmed, it's ready to use.

1. 1

   Go to Sender IDs

   In your Monster SMS dashboard, click "Sender IDs" in the left navigation bar.

2. 2

   Click "Add Sender ID"

   A form will appear asking for a display name and a mobile number. Enter the number starting with the Australian country code +61.

3. 3

   Click "Send code"

   Monster SMS will send a verification SMS to that number. Standard SMS rates may apply to the verification message.

4. 4

   Enter the verification code

   Check the phone and enter the 6-digit code. Once verified, the number appears in your Sender IDs list and is ready to attach to campaigns.

Option 2: Import a Twilio number

If you've been using Twilio directly and have a phone number there, you can bring it into Monster SMS without losing the number. This is useful if you've built up customer recognition around that number or have existing workflows tied to it.

The import connects Monster SMS to your Twilio account, so inbound SMS to that number routes through to your Monster SMS conversations inbox.

What you'll need

• Your Twilio phone number (e.g. +61 3 XXXX XXXX)
• Your Twilio Account SID (found in the Twilio Console under Account Info)
• Your Twilio Auth Token (same location, click to reveal)
• A display name for the number in Monster SMS

1. 1

   Go to Sender IDs

   In your Monster SMS dashboard, click "Sender IDs" in the left navigation bar.

2. 2

   Click "Import from Twilio"

   A form will appear asking for your phone number, Account SID, Auth Token, and a display name.

3. 3

   Enter your Twilio credentials

   Copy the Account SID and Auth Token from the Twilio Console (console.twilio.com). Enter the full phone number in international format including the +61 country code.

4. 4

   Click "Import from Twilio"

   Monster SMS will verify the credentials against Twilio's API and configure the number for inbound SMS. Once done, the number appears in your Sender IDs list.

Option 3: Alphanumeric Sender ID (Pro plan and above)

An alphanumeric Sender ID lets you replace a phone number with your brand name. Instead of +61 412 345 678, your customers see something like "CoolCafe" or "DentalPlus" in their inbox.

This option is available on the Pro plan ($125/month) and above.

Rules for alphanumeric IDs

• Up to 11 characters
• Letters and numbers only, no spaces or special characters
• One-way only — customers cannot reply
• Requires registration with Australian mobile networks (1-3 business days)

1. 1

   Upgrade to Pro or above

   Go to Settings > Billing to upgrade. Alphanumeric Sender IDs are available from the Pro plan at $125/month.

2. 2

   Click "Alphanumeric Sender ID Request"

   In the Sender IDs page, click this button and complete the registration form with your brand name and business details.

3. 3

   Wait for approval

   Monster SMS handles registration with Australian networks on your behalf. Approval typically takes 1-3 business days.

Which option is right for you?

• Starting out or testing: Add your own mobile number. Free on all plans, quick to set up, and supports two-way conversations.
• Already using Twilio: Import your Twilio number. Keep your existing number and move your workflow into Monster SMS without customer disruption.
• Running volume campaigns and want brand recognition: Alphanumeric ID on Pro plan. Best for retailers, franchises, and larger businesses sending regular broadcast campaigns.

Most businesses start with option 1 or 2 and move to alphanumeric later as volume grows. There's no wrong choice to start with.

Compliance and the Spam Act

Under Australia's Spam Act 2003, every commercial SMS you send must:

• Clearly identify who is sending the message
• Include a working unsubscribe mechanism
• Only be sent to people who have consented to receive it

A properly set up Sender ID covers the identification requirement. Your number or brand name tells recipients exactly who the message is from. Combined with Monster SMS's built-in unsubscribe handling, your campaigns are compliant from day one.

For a full breakdown of SMS compliance in Australia, read our Spam Act compliance guide.