Not sure but maybe the new Aust Post policy might work in your favour - if they weigh the package as they say they do during the sorting process, maybe there is some record somewhere of the actual weight?
As a parcel travels through our network, it’s checked by scanners that form part of our automated sortation process. This allows us to measure and record the parcel’s packaging type, dimensions and weight. The equipment that we use has been certified as Legal for Trade by the National Measurement Institute of Australia and enables us to charge you accurately.
The parcel details detected are then compared to what was declared when the label was purchased through MyPost Business. Underpaid postage will apply if there’s a discrepancy
