score:5
You do not need an original, but a normal photocopy will not do. What you can do, in your circumstances, is to present your passport application, with all except your parents birth certificate. Then it can be arranged to have your parent take their birth certificate to their local post office, and get the post office to certify it and fax it to the Passport Office. This is different to simply having it certified as there is a chain of custody from the certifying Post Office to the Passport Office.
As an alternative, there are other ways to provide supporting citizenship documents. One of with (that I never saw documented online) is to bring an old passport. Even if it is long expired (as can't be renewed), as long as it was issued after the year 2000, it can be used in place of a parent's birth certificate.
Upvote:2
I have been told by someone at the Passport Office that if I, a grandparent, can get my grandsons passport application number and take that to my PO (I live interstate) then the the PO can verify it on a B11 form that then goes to the Passport Office. This means I don't have to send my original birth certificate through the mail.