V Barcoded Machins
UM = Unmounted Mint (Mint Never Hinged)
VFU = Very Fine Used. Note that all VFU stamps will be provided on-piece, as self-adhesive stamps dissolve when soaked.
In March 2021, Royal Mail piloted their first-ever barcoded postage stamp; V4500. In 2022 they announced that they would be replacing all non-barcoded Machins with new barcoded stamps, and that from 2023 non-barcoded Machins would no longer be valid for postage.
Barcoded Machins are 50% larger than traditional Machin definitives. Similar to previous U numbered Machins, the new V Barcodes feature U-shaped slits, iridescent overprint, sometimes source codes, year codes, and self-adhesive backing paper.
Each stamp's 2D barcode, also known as a data-matrix, is unique. The barcode is added in a second stage of the printing process; the main design of the stamp is printed in Gravure, whilst the barcode is later added using Digital printing.