The wallets do NOT have serial numbers.
You should be able to tell if it's a fake from several things. First, the inside should be soft smooth leather, second the smell; It should not smell "plasticy" but like rich, delicious leather
Also, the zipper should be well made and the stitching even. I have lots of wallets and even ordered a couple from Bluefly and have never gotten a fake item from them...(despite some other people's experiences, I can only go by my own
You could take it to Neiman Marcus, Nordstroms (if one near you carries Chloe), Saks Fifth Avenue, or a Chloe boutique. You should be able to tell if you compare it to a handbag as far as the quality.
Some of the locks on the wallets, and other small accessories, are "upside down" as far that the "tree" shape of the locks.
This is a fluke, not a fake.
I have talked to "Chloe" about this and unlike the handbags (where you should NOT have the upside down lock), on some of the wallets, agendas, journals, etc., this was done inadvertantly by the factory. I have two agendas and some other Chloe accessories that have "upside down" locks. It's not a big deal and that is just the way some of the small leather goods were made
Enjoy your wallet. I will be surprised if it's fake from Bluefly!