The rules that govern the actions of those who are paid to prepare tax returns and represent clients with the IRS are found in Circular 230.

1. Your friend has received a letter from the IRS indicating a change to their tax return. Your friend believes the IRS is incorrect and wants to prove it. They believe they must hire a CPA or attorney to represent them to the IRS or the IRS will not listen to them.

2. Your brother believes that an enrolled agent who is authorized to represent clients to the IRS can never accept a contingent fee from a client. He says the IRS rules forbid this kind of arrangement.

3. A tax professional is asked to prepare the complex tax return of a both the husband and wife who are working through a messy divorce. She wonders if this could be a problem under the IRS rules.

For each of the scenarios, post your recommendation using the exact language from Circular 230. Provide any further explanation needed for your answer to be clear.