I'm not sure if I'm understanding you correctly.
When applying for a permit, you get the sign codes from the municipality in which your client's business is in or where the sign is going to go. You then propose a sign or refurbishing it to meet the codes of that jurisdiction. Then you apply for the permit to do the proposed work. pay the cost and then start said sign project.
If you want to move an existing sign because of high walls, you need to make sure the codes allow you to go to a height of understanding and then propose it. Otherwise, you might need to apply for a variance and those little suckers can be quite expensive.