Royal Mail delisting 1st/2nd NVIs without barcode

By January 31st 2023 it seems all Machin stamps will be invalid for postage and replaced with coded stamps, not just 1st & 2nd . It will be possible to exchange existing stamps for new, at current value.

So if you hold stamps in duplicate you’re better to trade them in and use the replacements for postage.

However if you have booklets , prestige packs etc which you have bought to hold as a collection, then forget the concept of monetary/ postage value, do not panic and despair , enjoy them for what they are and have faith in collector interest continuing.
Busted booklets and packs will be worth less without postage value, complete packs will hold some collector value.

Commemorative NVIs from mini sheets, prestige booklets it seems will continue to be valid.