If you are calling a mobile number, you don't need to add area code.All mobile numbers are 10 digits such as 0412 345 678.If you are calling from overseas, you add 61 and skip the 0. it becomes+61 412 345 678.If you call a land line, they are 8 digits 9123 4567If you are calling Perth from another city, you add 08 9123 4567If you are calling from overseas (such as China), it becomes +61 8 9123 4567.