Hello :)! You have a few options:
1. simply text ‘Menu’ to number 9999 and after options received, you can either choose “11 - Pay My Bill” or, retrieve your Account number by choosing “2 - Account Balance” and visiting http://www.optus.com.au/paymybill or calling 1300 309 309 to make payment.
2. access & pay your account online by simply logging in https://www.optus.com.au/my-account and click ‘pay my bill’ to choose from various payment methods. (Account number not required)
3. Access account online & view bill to retrieve BPay details/Account number - then you can schedule/make payments via online banking or phone banking.
4. Access Account online & set up direct debit