Paula.. just put down your contact details, list the item(s) that is/are being paid for, total cost, and you might as well state that you are not registered for (Australian) GST.
if you're really crazy, you could read the ATO definitions of a valid tax invoice.. but this is really for those registered for GST:
http://www.ato.gov.au/businesses/con...tent/50913.htm
and yes, i have an image shortlisted too
.
Phil