When you drop off a UPS package at the UPS Store, they will scan in each package as it is weighed on a scale. When they do this, they do two jobs: 1) confirm receipt of the package, and 2) re-weigh the package.

If you made a “mistake” on your shipping weight, UPS Store will catch it.

Same idea with post office.

Get a barcode scanner, or an iPhone that can scan/read barcodes and record the correct weight. If the shipping weight is different from what is recorded with the package, then airblow it off the conveyor belt for auditing.

This method wouldn’t be able to catch shipping method variances, but it could catch weight. Shipping method would need to be scanned based on other encoded data in the shipping label and/or reverse calculated based on the postage paid with dimensional weight possibly.

You would also have to encode the shipping weight paid for in the QR code of the shipping label.

I’m not for manual checking of package weight, when you can automate it. I imagine you could recoup the investment cost very quickly when you can catch postage due in an automated fashion. You could even bill the accounts of pc postage users by directly pulling from their postage accounts at the time of audit.