SMS texts are always free to receive from anywhere
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion. This is not Customer Service so we are unable to help with account specific issues.
@Claire101 If you want to send texts and emojis, download WhatsApp and tell your friends in Australia to download the app too. Texting, sending emojis, calling, and video calls are absolutely free over WiFi to anywhere.