This is a question we get asked from time to time.
Quick answer is NO. Not unless you want it to.
We only ask for your mobile number when you first register for your account in case we need to call you about your account.
But it does not appear on any SMS unless you specifically want it to...let me explain.
Our platform uses 2 "shared" numbers which allow text messages to be sent TO your people, and allow them to reply back into your account.
You can BYPASS the reply process by setting up a Custom Sender ID. This means you CAN make your messages come from your number if you wish (and replies come back to your handset).
Or you can use a word (11 characters)..note if you use a word then you cannot get any replies..but people can still optout using our Opt Out placeholders therefore keeping you spam-compliant. There's more info on Sender IDs here