When completing a Designation of Exempt form, we enter the TIN for the business we're exemption from CTR reporting. If a business has five "account numbers" under one TIN are all five accounts exempted from CTR reporting or just the accounts that meet exemption guidelines (such as 8 or more transactions per year in excess of $10,000)?

The exemption is for the customer, and covers all of that customer's exemptible accounts. You should include all of the customer's transaction, MMDA, and savings accounts that permit third party activity. Do not include accounts for which the customer is acting on behalf of a third party (such as a lottery account, or an account of a grocery store on behalf of various utility companies for which it accepts payments).