Short answer
A replica Hermes Birkin 40 is a bag made by a factory that is not Hermes. The 40 is the width in centimeters. Hermes does not authorize these copies. Selling them in the United States is a federal crime. This page covers the real bag's measurements, the parts copies miss, and the legal rules a buyer should know.
What the real Birkin 40 is
Hermes introduced the Birkin in 1984. The design came from a conversation between Jean-Louis Dumas and Jane Birkin on an Air France flight from Paris to London. The house names Birkin sizes by width. A Birkin 40 measures about 40 cm wide, 30 cm tall, and 21 cm deep. That is 15.7 inches by 11.8 inches by 8.3 inches. It sits above the 35 and below the 42 cm travel bag.
Sizes compared
- Birkin 25: about 25 x 19 x 13 cm
- Birkin 30: about 30 x 22 x 16 cm
- Birkin 35: about 35 x 25 x 18 cm
- Birkin 40: about 40 x 30 x 21 cm
The 40 holds a laptop, a folder, and a small pouch. Resale demand for the 40 is lower than for the 25 or 30, so secondhand prices sit below those sizes.
Leathers and hardware
Common Birkin leathers: Togo (pebbled calf), Epsom (embossed calf), Clemence (heavy grain), Swift (smooth), Barenia (saddle leather), and Box (polished calf). Hardware comes in gold plate, palladium, permabrass, and rose gold. A Birkin 40 exists in most of these combinations.
Parts copies get wrong
- The blind stamp. Hermes presses a leather code, a year letter, and an artisan number into the front flap. The year letter changes each year.
- The stitch. Hermes uses a saddle stitch, two needles and one waxed linen thread, on the handle and flap. Machines make a lock stitch, which looks different on the back side.
- Hardware weight. Real hardware is plated brass. Copies use stamped steel or zinc.
- Engraving. Real clochette hardware carries the Hermes name in filled lettering. Copies etch the surface.
- The leather itself. Vegetable-tanned leather has an earthy scent and a soft fall. Chrome-tanned leather smells of chemicals.
Copies can match the silhouette and the color. They do not match the saddle stitch, the stamp, or the leather. Some listings marked 1:1 or mirror use a year letter that does not exist.
Money
Hermes does not publish Birkin prices and does not sell the bag on its website. Stores sell to established clients. Counterfeit listings quote hundreds of dollars. Real Birkin 40 resale prices reach five figures. A low price is a signal the bag is a copy. No authority tracks counterfeit pricing, so totals in that market are unknown.
US law
Hermes owns the Birkin trademark. Registration covers the word mark, the hardware design, and the bag shape. 18 U.S.C. 2320 makes trafficking in counterfeit goods a federal crime. A first offense carries up to $2 million in fines and 10 years in prison. 15 U.S.C. 1114 gives the trademark owner a civil claim for damages and lost profits. US Customs and Border Protection seizes counterfeit shipments and destroys them. A buyer who pays a foreign seller has little recourse if the parcel is seized.
How to inspect a bag in hand
- Read the blind stamp. Format is leather code, year letter, artisan number.
- Count stitches per inch on the handle. Hermes counts are fine and even on both sides.
- Turn the hardware. Check engraving depth and font.
- Smell the interior. Vegetable-tanned leather has an earthy scent.
- Check the heft. Plated brass adds mass at the turnlock and the rings.
Limits of this guide
This page does not sell bags. Hermes publishes no Birkin 40 measurements, so the numbers above come from auction houses and resellers and shift with the leather. Anything about counterfeit quality comes from inspection reports, not from factory data.