If you call suspenders braces, you are either British or a sartorially-inclined gentleman. Braces is the term the Brits use for the accessory.
After all. Purists will also tell you that braces use leather or cloth straps to attach them to buttons sewn on the inside of the trouser waist.
Suspenders, on the other hand, can be fastened with metal clips. For some, this is the distinction between the two.
This is mostly an American term as the Brits use it to describe what we’d call in the US, a garter belt to hold up hosiery.
SO WHICH ARE YOU?