If you need a postmark applied to your philatelic item, head to your local Post Office. Only authorised Australia Post staff can apply postmarks. Make sure you’re getting the right kind of postmark applied. You’ll want a national postmark on a first day cover, the correct commemorative postmark for a special occasion stamp, and so on.
Request that the postmark impression is applied with clarity and precision - no smudging! Black is the only colour ink that should be used. Catch the corner of the stamp - don’t cover up the stamp design. Refer to the images below as a guide.