Is the Knowledge for Chargeing the Fee in Just One Place?

Would it be fair to say that the knowledge for charging the fee and the calculation for that belongs in just one place yeah I think it depends I mean it depends on the knowledge in that way. If there is like repetition or you know the duplication of this rule in different places it's a sign that you are indicating knowledge but I think you can detect that because if the rule changes and you're updating the same code in different places  it means that maybe because the knowledge is the same technology is duplicated in different places.