I opened a return of an item as literally the wrong item had been sent. I put the item back in original packaging and brought to post office. I had the QR code ready on phone. The post office teller immediately scanned the bar code on the original packaging. I asked did he not need the QR code and he said something to the affect that it's just the same thing. I notice now on the eBay return request that the fact that Royal Mail now have the package it has not registered as such on eBay...

Returning Item: Post Office scanned original barcode - not new QR code | Postage

Returning Item: Post Office scanned original barcode - not new QR code | Postage | eBay UK