The Practical Reality of Louis Vuitton Date Codes
Most people calling them "serial numbers" are off by one. Louis Vuitton never issued unique serial numbers the way Rolex or Patek Philippe did. Every item from a given batch shares the same date code. That distinction matters because it changes how you approach authentication, research, and pricing. A date code is a stamped or sewn-in marker that tells you where and when a piece was manufactured. The format shifted several times across the brand's history, which is why so many guides get it wrong. Pre-1980s items often have no code at all, or just a simple factory mark. From 1989 through early 2021, the standard format was two letters followed by four digits. The letters identify the workshop, the digits encode the week and year of production. After March 2021, Louis Vuitton moved to microchips and phased out date codes entirely, which means any guide claiming to cover "all" Louis Vuitton items needs to address that cutoff explicitly or it is incomplete. Here is the format breakdown that actually works in practice:
AA, AB, AC, etc. represent the manufacturing country and workshop. Common ones you will encounter: AR and AZ for France, TH and FL for the United States, HI and BO for Spain, SD and OH for Italy, MI and DA for Germany, BR for Brazil, and TU for the Philippines. A code like AR2141 means France, 21st week of 2001. The third and fourth digits are the year. The first two are the week. Simple enough on paper. The complications start quickly. Some codes look valid but do not correspond to real workshops. The letter combination AU, for example, never appears in authentic LV goods and shows up frequently on fakes. BI is another one counterfeiters love because it looks plausible but is not an authorized code. FL is a genuine US code, but it was only used at specific factories during narrow windows, which means a bag dated FL1099 might be legitimate or it might be a retro-stamped fake depending on the style in question.
Where to Find the Code on Different Products
Location varies by item type and era. Handbags typically have the code on a leather tab inside the bag, often along a side seam or near the interior pocket. Some older styles stamp the code directly onto the interior lining fabric instead of a leather tag. Wallets and small leather goods usually have it stamped on the interior leather panel, sometimes near the zip or on a hidden strap. Accessories like scarves and belts use fabric tags with the code printed rather than heat-stamped. Shoes often have the code inside the shoe box rather than on the product itself. I once spent an afternoon tracking down a date code on a vintage Neverfull MM that a seller claimed was from 2006. The code was stamped on the interior fabric, nearly invisible against the Damier Ebene canvas. I had to angle a bright LED light at roughly thirty degrees to read it. The code came out as SP1198. Everything about the stamp depth, font weight, and leather tab quality checked out, but the bag had been cleaned with a solvent that had blurred part of the second digit. It could have been read as SP1188 or SP1198. I cross-referenced with known authentic examples from the same batch and confirmed the third digit was a nine based on the stroke pattern. This is the kind of marginal call you deal with regularly, and it is why date codes alone are never sufficient for authentication.
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Reading the Dates
The four-digit portion breaks down into two parts. For codes before 2007, the first two digits are the week and the last two are the year. For codes from 2007 onward, the format reverses: the last two digits are the week and the first two are the year. So DD99 means 99th week under the old system, which does not exist because there are only 52 weeks in a year, while 99DD means the 99th week of year 2009, which also does not exist. People get tripped up here constantly. If a code has six digits or reads in a way that produces an impossible week number, it is a red flag. There is also a less commonly discussed nuance. Louis Vuitton does not produce 52 weeks per year in the traditional calendar sense. Their production calendar uses a different counting system, and certain weeks are skipped or repeated depending on factory holidays and seasonal rhythms. This means a code like AR0501 could theoretically represent the 5th week of 2001 but might actually correspond to a slightly different calendar date depending on which factory produced it.
Counterfeit Patterns You Will Encounter
The most common fake code issue is wrong font. Genuine LV date codes use a very specific dot-matrix style stamp. The dots are uniform in size and spacing. Counterfeit stamps tend to be either too shallow with faint dot patterns or too deep with merged ink bleeding between dots. Another tell is alignment. On authentic items, the code is generally straight and level relative to the surrounding seams and edges. Fakes often have codes that are tilted or placed at odd angles. A more sophisticated counterfeit practice involves using real date codes from discarded authentic parts. Someone might take a genuine leather tag from a damaged bag and stitch it into a fake one. This is why you cannot authenticate solely by matching a code to a database. The code itself might be real while the bag it is attached to is not. I have seen this happen with high-end reproductions that sell for $800 to $2000 on secondary markets. The code checks out, the hardware feels heavy, the canvas smells right, but the stitch count per inch is slightly off and the interior lining material is a cheaper substitute.
Limitations of Date Code Research
Date codes have significant limitations that most guides ignore. First, they cannot verify authenticity on their own. Second, the public databases are incomplete and often contain errors passed down from one forum to another. Third, Louis Vuitton changed its coding system multiple times, and the transitions were not clean. Items produced during transition periods may have ambiguous or hybrid formats. Fourth, items made before 1989 may lack any date code entirely, and items made after March 2021 use RFID chips instead. The most practical approach combines date code verification with physical inspection of multiple authentication points: stitching quality, canvas alignment at seams, hardware engraving depth and font, zipper maker markings, and interior construction details. No single factor is decisive, but a convergence of inconsistencies across multiple points is. If you rely exclusively on a date code lookup, you will miss counterfeits that use stolen authentic codes or produce codes that happen to match real workshop and week combinations. For ongoing reference, the Louis Vuitton Serial Number Guide framework most people search for is really just a decoding system for date codes with no standalone authentication power. It is useful for dating pieces and identifying likely origin, but it was never designed as a definitive authenticity tool. The brand itself does not publish a comprehensive public database, and third-party databases are community-maintained at best. Treat them as starting points for investigation, not as verdicts.
