Infant under 2 year old
For the purpose of travel on jetstar, an infant is defined as being not yet 2 years of age at the time of travel
ID requiements
For infant not occupying their own seat ,proof of age(under2)may be require,such as a birth certificate or passport (required for international travel). if you do not provide an acceptable form of identification upon request of check-in ,then you may not be allowed fo travel.