Royal Mail surcharge.

[squidgyicecream]

Royal Mail have added a surcharge to an item I've sent out to a buyer, I've sold several different vinyls recently. Some buyers have brought more than one all delivered fine and the same way yet this single item that would weigh less ams be smaller than the multiple items sent has a surcharge applied saying I haven't paid enough postage, just waiting for the buyer to send me the details and confirm this as surely Royal Mail can't do this? Any advice would be great thanks.

[moldosgifts]

Advice would depend on how you sent it.

Was it at the post office, was in an OBA,

Was it weighed at home was it weighed the post office.

[squidgyicecream]

Was sent Royal Mail tracked 48 small parcel up to 1kg weight was no more than 375g it was a 12" record. 

Thanks

[moldosgifts]

At the post office or put into a grey sack with manifest?

[squidgyicecream]

Pre printed label at home and dropped off at the post office and scanned in by them.