1. Stitches
The stitching on a Louis Vuitton bag will always be perfect, without any loose threads or unevenness. The thread will be mustard colored, and not a lighter shade of yellow.

2. Monogram
If there is a monogram on the bag, it will always be completely straight and symmetrical. In the LV logo, the L will always be slightly lower than the V. The letters are perfectly straight and perfectly aligned, if they are soft this is a sign of a copy.

3. Brass fittings
Brass fittings on a Louis Vuitton bag, like the other parts, are always of high quality. It either comes in a shiny or matte material. You will be able to see yourself reflected in the shiny material (note, however, on older vintage bags this can be difficult).

The zipper will feel robust and not loose when zipping up / down. There will always be Louis Vuitton's own logo on the zipper, and not YKK or anything else.

4. Leather
The leather on the handles and details on a Louis Vuitton bag will darken over time and acquire a patina. You will also be able to smell the characteristic leather smell on the bag.

5. Lined
The inner lining of a Louis Vuitton bag will always feel soft and delicious. If it feels stiff or like plastic, this can be a sign that it is a copy.

6. Date code
Most Louis Vuitton bags do not have a serial number, but instead a date code. The date code tells where the bag was made and when. It is therefore not the best way to check whether a bag is genuine.

Before 1980: no date

Early 1980s: three or four numbers representing year and month. e.g. "841" will mean that the bag was made in "84" (1984), and the 1st month (January).

Late 1980s: three or four numbers followed by two letters indicating where the bag was produced. See an overview below of all codes.

1990 to 2006: two letters followed by four numbers. The letters represent the locality, and the numbers year and month. Here is the code e.g. "BU1013"
BU means France The 1st number is combined with the 3rd so in this case it is the 11th month (November) and the 2nd number with the 4th is 03 so the year is 2003.

2007 to 2021: Same arrangement as before "BU2126" but instead of month by 1st and 3rd digits, this is by week. So week 22 of the year 2016.

2021: there is no more date code, but instead digital microchips.

Here is a selection of classic Louis Vuitton bags:
Noé , Keepall & Neverfull