When it comes to durability, we doubt any billfold you purchase can match the William Wallet, with its rubber-banded aluminum sheets and dead simple design. If you still prefer the feel of leather on your backside, though, the Uni-Fold Wallet might figure as your most long-wearing option.
Designed by Noah Lambert, the pocket accessory pulls the durability card by minimizing the parts of a wallet where damage usually begins: the joints. Instead of multiple seams to connect one cut part to another, there's only two, with one on the left end and another on the right. Everything else is just created using slices and folds.
The Uni-Fold Wallet is made from a single sheet of leather that's been folded and sliced for turning into a functional billfold. While there's no window for an ID (to minimize easy-to-damage parts), it comes with a bill-sized main compartment and two areas for cards on either flap. There's nothing fancy about the appearance, but the single-sheet design should ensure it lasts longer than other leather wallets you can get your hands on.
The seams are saddle-stitched by hand using a material and technique that's supposed to be twice as durable as a common lockstitch. Material is 5-oz. vegetable tanned bridle leather, sourced exclusively from Wickett & Craig of Pennsylvania.
Want one? The Uni-Fold Wallet is available directly from Noah Lambert's website, priced at $90.