[FuzzyDunlop]

I used to be a Tesco employee for a fair while, and it wasn't difficult to notice this pattern purely because those barcodes don't always scan (typically due to dodgy equipment).

It would often be the case that you couldn't see the whole code on the sticker, but could infer it by removing it and using the original barcode and a bit of guesswork.

I don't advocate the testing of this, and any observant member of staff will have no difficulty catching you out.

[lucaspiller]

+1 I can still remember the barcode for Cadbury's Creme Eggs even though I left Tesco 5 years ago.