Passing on Different Caller IDs when Forwarding Calls

In this post, I’ll assume you know how to create LaML bins and assign them to numbers. If you don’t know how to do this, I recommend checking out our documentation page:

How to Forward Calls

If you followed the steps on this documentation, you’ll end up with a forwarding bin like this:

<?xml version="1.0" encoding="UTF-8"?>
<Response>
    <Dial callerId='{{From}}'>123-456-7891</Dial>
</Response>

In this example, the call will be forwarded to 123-456-7891 and the caller ID will display the original caller’s phone number. But let’s say you’re forwarding these calls to your personal number and you want to know the difference for when an inbound call is personal or business related. You could alter this bin to display the number dialed using this:

<?xml version="1.0" encoding="UTF-8"?>
<Response>
    <Dial callerId='{{To}}'>123-456-7891</Dial>
</Response>

When this call is forwarded to 123-456-7891, it will display your SignalWire number that your customer dialed so you know this is a business related call.

You can of course input a direct phone number into the caller ID parameter instead of using the To and From variables, but you’ll only be able to use another SignalWire number you own or a number you have verified on your account.

Passing on Two Caller IDs

Wouldn’t it be great if you could display two caller IDs so you know the original caller’s number and the number they dialed? Unfortunately devices can only display one number in the caller ID field, but we can use SMS as a work around to text us additional information about the call. Take a look at this bin:

<?xml version="1.0" encoding="UTF-8"?>
<Response>
   <Sms to='123-456-7891' from='+18882223333'>Inbound call to {{To}}</Sms>
   <Dial callerId='{{From}}'>123-456-7891</Dial>
</Response>

When an inbound call comes in, this bin will send an SMS to 123-456-7891 that says what number this inbound call dialed. The call will then be forwarded and the caller ID displayed will show the original caller’s number. All of these actions happen within milliseconds so you’ll receive this SMS right as your phone begins ringing.

In this example, I’m sending the SMS from the toll-free number +18882223333. I do this because in order to send SMS, you need to register your phone number. 10DLC (local code) phone numbers need to be registered with The Campaign Registry while toll-free numbers have a different verification process. Registering 10DLC numbers with The Campaign Registry can be expensive as there are various startup fees and recurring monthly fees. Toll-free verification does not have these same fees and since I’m only using this number to send an occasional SMS, it’s more cost effective to use a toll-free number. If you need to verify your toll free number, I recommend checking out this documentation:

Toll Free Verification

If you’re still interested in sending SMS using a 10DLC number, I recommend checking out our extensive documentation about The Campaign Registry:

The Campaign Registry - Everything You Need to Know