Question: how to check data balance on optus prepaid?
Answer: Monitor your usage & Prepaid balance via My Account.
Take note of automated usage alerts sent via SMS (compatible plans only)
Check your usage or balance via SMS: Text the number 1 (one) for balance or the number 2 (two) for usage to 9999.
Check your Prepaid balance by calling: 1509.
Download the My Optus app.