Flip almost any authentic fragrance over and you will find a short alphanumeric code printed or stamped near the base — something like 7A02 or R240. It is easy to ignore, but that batch code is one of the most useful things on the bottle. Perfume houses use it to track when and where a bottle was filled, which means you can use it to work out roughly how old your fragrance is.
Why does age matter? Fragrance is mostly alcohol and oils, and both change over time. A well-stored bottle can stay beautiful for years, but citrus-forward and lighter scents fade fastest, and heat or sunlight speeds everything up. A batch code that decodes to a recent year is a good sign of a fresh, honestly-sourced bottle; a very old code on a supposedly brand-new purchase is a reason to ask questions.
You do not need special tools. Free batch-decoder sites let you type the brand and the code and return an approximate fill date. It will not be exact to the day — houses format codes differently — but it is usually accurate to the month or season. Pair that with an intact seal, clean printing, and a cellophane wrap that fits snugly, and you have done ninety percent of an authenticity check in under a minute.
Every lot we sell is verified before it ships — batch checked, seal checked, sprayer checked — but we would rather you know how to do it yourself. A collector who can read a batch code is a collector who never overpays for an old bottle.