Illinois Regulated State tattooing of minors is prohibited http://www.aaatattoodirectory.com/tattoo_regulations.htm
It is 18 in OZ, that's also our drinking age. I think we have different standards than others do although a lot are the same. These our legal age standards: http://www.yfs.org.au/legal/age.shtml
well u can get tattoes in illinois at really ne age but if ur a minor u need permission from neone over 18.