Elena Rostova

Every Louis Vuitton date code format from the early 1980s to the microchip, with worked examples, the workshop letters, and what a code can and cannot tell you.

Every Hermès bag carries a small letter that dates it. Here is the full year chart, where to find the stamp on each model, and what it really tells a buyer.

The sticker inside a Chanel bag dates it to within a year or two. Here is the full year table, where to find the number, and why it is never proof on its own.

The numbers inside a Gucci bag are a style code, not a date code. Here is what they mean, where to find them, and how to use them to check a pre-owned bag.

Codes, cards and packaging are copied routinely. These are the checks that still tell you something, and the point at which to stop and ask an expert.