Did you buy the dog as a pure bred Black and Tan coonhound? Cuz if it stated 'pure bred' you have to be able to register him. Is he registered? Were the parents?
If the parents weren't registered, they probably weren't pure, for whatever reason.
Looking at the pic of your dog, versus the standard for Black and Tan's.. i'd say he is a mix as well. BEAUTIFUL and STUNNING but possibly a mix.