do I have to have credit to text a friend in Australia

[dalyer]

I presume that your friend is using an Australian mobile number?

International texts are not covered by membership/add-on allowances.

You need cash credit on your account to pay for international calls and texts.

See here:

• https://48.ie/charges/international-calls

You'll also need an active membership in order to be able to send international texts or make international calls.