An informative guide taken from TheBrownPaperBag

FACTS ABOUT LOUIS VUITTON PRODUCTIONS

Serial Numbers
Typically, Louis Vuitton will assign serial numbers to items that have been manufactured in their Special-Order workshop in Asniéres-Sur-Seine, France. Rather than being offered for sale in their boutiques, these items are often made to order by dedicated craftsmen in this small workshop.

The French Company
From 1970's through 1991 Louis Vuitton and The French Luggage Company in United Stated had a collaboration/licensed relationship. Goods therefrom have other markings and no date codes.

Pre 1980s
Louis Vuitton goods manufactured prior to 1980 have no date codes and can only be authenticated by meticulously inspecting the construction: brass pieces, hardware, lining, leather quality and condition, stitching etc.

Early 1980s
Louis Vuitton starts marking their goods with three to four digit Date Codes, representing the month and year when the particular item was manufactured. The first two numbers represent the year and the last number(s) the month i.e. "836" would indicate that the item was manufactured in the sixth month (June) of 1983.

Mid to Late 1980s
Louis Vuitton ads two letters to the previous three to four digit date code. The letters represent the factory location. "VI8610" would thus indicate that the item was manufactured in France, October 1986. On some pieces the date code may be split up, showing the letters in one place and the numbers in an adjacent area. In the late 1980's, standards were set in place that ensured letters to always be placed before the numbers.

1990 to 2006
By 1990 some date codes were given a new format; having the year and month digits staggered. The first two letters represent the country, the first and third number represent the month, and the second and fourth number representing the year i.e. "SD0070" would indicate that the item was manufactured in USA in the 7th month (July) of 2000.

2007 and Later
In 2007 Louis Vuitton made further changes - date codes are now in week format. The first two letters represent the country, the first and third numbers represent the week of the year, and the second and fourth number representing the year i.e. "VI3058" would indicate that the item was manufactured in France in the 35th week (late August) of 2008.

Factory locations & letter abbreviations

France: A0, A1, A2, AA, AAS (special order), AH, AN, AR, AS, AX, BA, BJ, BU, CO, CT, CV, DR, DU, ET, FL (also USA), GR, IT, LW, MB, MI, MS, NO, RA, RE (also Italy), RI, SA (also Italy), SD (also USA), SF, SL, SN, SP, SR, TA, TH, TJ, TN, TR, TS, VI, VX

Germany: LP

Italy: BC, BO, CE, FA, FO, MA, NQ, PL, RC, RE (also France), RO, SA (also France), ST, TD

Spain: CA, CR, JI, LB, LM, LO, LW

Switzerland: DI, FA (also Italy)

USA: FC, FH, FL (also France) LA, OS, SD (also France), FL