A Gentle Correction to Online Cosmetic Batch Code Checkers for Modern Guerlain Products


Image of a Guerlain batch code (2J01) stolen shamelessly from our dear friend Monsieur Guerlain, to whose wonderful site we insist you go.

It is with great sadness that we report to the PERFUME LITERATURE otherwise known as the fragrance community otherwise known as the worldwide brotherhood and sisterhood of perfumistae otherwise known as (*shudders*) “fragcomm” that NONE of the three (3) online batch code checkers are functioning properly for Guerlain.

Yes.  You read that correctly.  Guerlain.  As in GUERLAIN.

Stated differently, we are apparently getting FAKE NEWS from all three weather channels for the age of our Guerlain fragrances.


Those channels are:



And the latest entrant, who also has a wonderful Pinterest board!


Here is a very specific example of the problem.

I have a bottle of L’Instant de Guerlain Pour Homme EdT which I bought in 2008 from a store in America.

Now, I would rather not say to whom this fine establishment belongs, because it will become clear momentarily that they were selling old stock from France as a money-making venture, rather than binning the stuff or sending it to discounters.

Old stock, as in PRE-VINTAGE.  Yes.  The good stuff.  I mean – why the heck would anybody use an online batch code checker anyway?  To see if stuff was fresh?


Anyway, it turns out that ALL THREE batch code checkers say that the batch code of 4H06 corresponds to August 2014.

This is simply NOT TRUE.

Apart from the obvious fallacy that a fragrance bought in 2008 could not have been made in 2014, two things.

First, I have used my entire collection of Guerlain fragrances against the batch code checkers, and have thereby discerned that they are FAILING for every fragrance with a 4-character batch code prior to 2008.  Thus, the only sensible date for the exemplary fragrance in question is August 2004.

Closer inspection of my collection shows that their algorithms are correctly interpreting the YEAR character and the MONTH character, but they are not adhering to the fact that the two sets of month characters in use by Guerlain ALTERNATE by decade, thus turning what would be a 10-year cycle into a (maximum) 20-year cycle.

In fact, that entire cycle appears due to repeat this January (2018).

Thus, it would be nice if the online batch code checkers could fix things fairly soon.

Secondly, for those who are unfamiliar with the Guerlain batch code systems (plural), they were nicely elucidated by Andre Moreau of Raiders of the Lost Scent in the following post:

Additionally, Monsieur Guerlain….


discusses the modern codes (the ones we are talking about) very clearly in the following post, which I highly recommend:


According to both Andre Moreau and Monsieur Guerlain, the current month table using N-Z was begun in 2008, and this is fully confirmed by my own collection of bottles, which only make sense if dates prior to 2008 are using A-M for the month table.

Thus, because we are now at the last month of a 10-year cycle on the FIRST DIGIT using the current letter set for the month (M-Z) on the SECOND LETTER, for Guerlain to achieve maximum utility from their own batch code scheme, they will need to switch to the A-M month table beginning in January.

The batch code checkers are already confusing dates from 2002-2007 with dates from 2008-2017 needlessly.  If they don’t fix this bug, they will be confusing 2008-2017 with future dates, going forward.

Here is the proper algorithm:

4-character code of form NLNN (N = number, L = letter)

First digit = last digit of year

Letter = month in either set A-M excluding I or N-Z excluding O

Find latest POSSIBLE date (meaning not in the future) assuming that months alternate as follows:

2002-2007 A-M

2008-2017 N-Z

2018-2027 A-M

Now, having said all of the above, this blog post must be brought to the attention of these online batch checkers, which in the case of CheckFresh is supposed to be via Facebook.

WE are not on the dreaded FACEBOOK for REASONS that we won’t get into here, as a courtesy to our beloved Monsieur Guerlain, who IS in fact on Facebook and must not be allowed to worry about such things, since said REASONS don’t apply to HIM.

Thus, we ask that anybody so motivated please let CheckFresh on Facebook know that they have a WEE BUG in the Guerlain module which could use some fixing.  If so desired, you may direct them to this post.

WE will attempt to contact the others, although others are welcome to do so as well.

NOW – you may be asking yourself this question:  WHY on earth do we CARE about this silly thing?  This tempest in a perfume bottle?  This Y2K among Y2Ks?




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