Locally, there are a few different companies offering globalroaming SIMs, including GlobalSIM, TravelSIM, GoSIM and GoTalk. We haven’t tested these services and so can’t recommend one – you’ll need to compare prices and find one to suit you. As a guide, we found one offering data rates starting from 49c/MB and another offering rates of 79c/min to call an Australian landline from the UK. You can buy these SIMs in Australia or the country in which you’re travelling. Your phone needs to be unlocked to do this – see below.
Another options just launched is Globalgig hotspot. It is a small wireless dual-band GSM/CDMA hotspot device that locates and switches to the local Globalgig network partner automatically when overseas so users can access the internet. The device cost is $129 with monthly plans from $25 for 1GB.
Telstra global-roaming data packs start at $29 for $150 of value for post-paid accounts. Using Telstra’s data calculator, this $150 equates to approximately 10MB in data, which means that each 1MB costs about $3. Without a prepaid pack, Telstra charges $15 per MB for the pay-as-you-use globalroaming data.
Optus charges $45 for 50MB of data with a prepaid data pack. This means that each 1MB costs just under $1.
Vodafone charges $50 for 100MB for a data pack for European destinations. Pay-as-you-go roaming is 1c/ KB for plans and 5c/KB for prepaid ($10 for 1MB and $50 for 1MB).
Cost calculators are useful if you want to try and work out how much phone or internet usage you might want and the approximate cost -Telstra as well as Optus and also Vodafone have them available on their websites.
Unlocking your phone
Smartphones bought through a telco service provider such as Telstra or Optus are almost always “locked” to their net works. This means the phone can only be used on that network. While this isn’t an is sue for use with that carrier in Australia, it can be problematic if you want to use an alternative SIM card when travelling overseas to get cheaper rates for phone calls and internet access. To unlock the phone, you need to ring your ser vice provider and request a code. However, you'll be charged a fee that can range from $50-150 depending on the device and whether it’s on a plan or owned outright.