Nope, bank account number has no relation to the postal address of a bank, each branch has a unique sortcode and therefore a sortcode can be used to locate the bank branch. that link i provided can be used without entering in an account number.
Not actually true. Several branches can share a sort code (I know of 5 around here with just one code between them) and one branch can have several sort codes (I know of one with three)
and the sort code being asked about isn't actually a branch......