Optus offers data roaming for post- and pre-paid plans to a set of 'zone 1' and 'zone 2' countries as well, which can be viewed on a map on the telco's site. Zone 1 countries are charged at a cost of 50 cents per megabyte, and zone 2 countries at $1 per megabyte. This is in addition to what you pay for your regular mobile access.
Which should you choose?
If you have little to no intention of using your mobile phone for voice and text messaging while overseas, but instead require a good amount of data, Globalgig's data-only plans are worth considering, primarily for their simplicity, and for their adequate data allowance. The expanded list of countriesd in which the service works, as well as the benefit of one APN for home and abroad, also make it a good choice for businesses.
Existing users of Globalgig can use current SIM cards to upgrade to the new 4G Flexi and Go Europe+USA plans, but a new SIM will be required for the Go Global plan, mainly because it carries a lot more profiles that it needs to work in all of the new countries that are now supported.
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