Telstra will alert customers using mobile data while roaming overseas every time they spend between $17.57 and $307 on 20MB.
The carrier today introduced SMS data alerts for every 20MB used while overseas, for every country except Hong Kong.
Telstra's deputy CFO Mark Hall told a Macquarie Australia Equities Conference today (pdf) the alerts were being introduced because "some customers don't fully appreciate" how much data is consumed by smartphones, nor the cost of using certain apps overseas.
Using 20MB of mobile data while roaming will cost Telstra customers between $17.57 and $29 if the customer prepays for an international casual traveller data pack.
The $17.57 for 20MB price requires the top-of-the-range $1800 data pack.
Without a data pack, Telstra charges 1.5 cents per KB — or $307 for every 20MB — for mobile internet while roaming overseas.
The international data roaming packs were revamped earlier this month, providing a substantial increase in data allowance compared to the original packs launched in February last year.
Telstra has been focusing on bill shock in recent years after the phenomenon saddled the carrier with millions in bad debts.