What should be included in a tax professional's fee agreement before I sign and pay them?

A proper fee agreement must include: (1) Scope of work - exactly what services they'll provide, (2) Total fees and what's included, (3) Payment schedule, (4) Refund policy, (5) What happens if the case is rejected, (6) Termination terms, and (7) Both parties' signatures. Never pay without a detailed written agreement.