If we appeal to tribunal, how does the process actually work? Is this like the small money claims process where you wait until they take to court and then make representations? What is the worst case scenario costs? Will it still be £160 if tribunal outcome is to pay?
It's slightly different because you have to take them to the tribunal, and then they have to prove that the penalty is payable, but you can rebut that by establishing a statutory ground of appeal. In practice if one of us represents you, then we'll take care of all of that for you.
The absolute worst case scenario is that you have to pay the penalty charge of £160, the tribunal itself is free to appellants (the authority pays a tribunal fee regardless of the outcome, but you don't have to worry about that).