Coles Mobile does offer international roaming, but it isn't as cheap or convenient as some of the other options available to Australian consumers. Regardless of whether you're on a prepaid or postpaid Coles Mobile plan, international roaming will cost you $25 to add on. Calls and texts made outside Australia using a Coles Mobile SIM will cost you based on the MVNOs current roaming rates. These vary but can be found on the Coles Mobile website. Once you've used up your $25 of included value, you'll have to top up. Unused roaming credit expires after 30 days.