You do not need to have a referral to see a hand therapist. A referral is preferred if you are paying privately and claiming through your health fund.
A medical referral is necessary from your treating surgeon or GP if you are covered by an insurer such as WorkCover, QBE, GIO, Allianz, AAMI, or DVA. You will need to bring your insurance details to your appointment (ie. Claim number).
It is helpful to bring with you any operation notes, x-rays and other investigations such as MRI or ultrasounds you may have.