Book excerpt: Processes still have not been established to link employers with all third-party payers. Of the four most common types of third-party payer arrangements, only Reporting Agents and Section 3504 Agents are required to submit an authorization form that discloses the relationship between an employer and a third-party payer. The IRS does not require a similar authorization for employers that use a PSP or a PEO. The inability of the IRS to identify employers that use the services of a PEO is a concern TIGTA raised in prior reports. In addition, authorization forms are not always accurately processed. Our review of 85 agent authorization forms processed in Calendar Year 2013 identified 11 forms with errors. Because of these errors, authorizations provided by employers to their Reporting Agents were incorrectly reflected in IRS systems. Finally, the IRS has not established an effective process to ensure that indicators are accurately assigned to Section 3504 Agent and employer tax accounts. Our review of the tax accounts associated with Section 3504 Agents filing 78 Forms 2678, Employer/Payer Appointment of Agent, identified 13 that contained erroneous indicators. The errors incorrectly identified Section 3504 Agents as employers and vice versa.