Okay. In the context of roaming, receiving SMSes are free. This applies to all carriers, and in most cases you'll be able to receive SMSes as long as your SIM card is able to register on the local networks.
Receiving/making calls, sending SMSes, and using data will incur charges - in case of prepaid, the actions (other than receiving SMSes) will simply fail if you don't have an active roaming paket.
That being said, on Telstra you could just disable your day pass and you'll still be able to receive SMSes, just not do anything else while overseas, which is what I did during my recent trip back home. Not sure about Optus/Vodafone as I don't use them.
Okay. In the context of roaming, receiving SMSes are free. This applies to all carriers, and in most cases you'll be able to receive SMSes as long as your SIM card is able to register on the local networks.
Receiving/making calls, sending SMSes, and using data will incur charges - in case of prepaid, the actions (other than receiving SMSes) will simply fail if you don't have an active roaming paket.
That being said, on Telstra you could just disable your day pass and you'll still be able to receive SMSes, just not do anything else while overseas, which is what I did during my recent trip back home. Not sure about Optus/Vodafone as I don't use them.