What does contracting with a CPEO mean for my business? Employers may enter into a service contract with a certified professional employer organization (CPEO) in which the CPEO agrees to take over some or all of the employer’s federal employment tax responsibilities and obligations. Form 8973PDF, Certified Professional Employer Organization/Customer Reporting Agreement, must be filed to notify the IRS of the start and end of contracts between the CPEO and its customers. Generally, the CPEO is solely liable for paying the customer's employment taxes, filing returns, and making deposits and payments for the taxes reported with regard to remuneration it pays to work site employees (as defined in IRC 7705(e)). However, a CPEO and its customer may both be liable with regard to remuneration the CPEO pays to non-worksite employees. For a detailed definition of work site employee, see Revenue Procedure 2017-14PDF section 1.01(16). A CPEO files aggregate employment tax returns for all its customers using the CPEO’s employer identification number (EIN). The CPEO must attach the appropriate Schedule R, Allocation Schedule for Aggregate Filers, to its employment tax return and allocate to each customer the information reported. The CPEO deposits and pays the tax liabilities of those customers using the CPEO’s EIN, according to the CPEO’s deposit requirements. CPEO customers cannot view federal tax deposits and payments made by the CPEO using the Electronic Federal Tax Payment System (EFTPS). For additional information on employers outsourcing their payroll responsibilities, see Outsourcing Payroll and Third Party Payers. Public Listing of Certified Professional Employer Organizations The IRS will publish a list of all organizations that are certified as CPEOs, and the effective date of their certification on the Voluntary Certification Program for Professional Employer Organizations (CPEOs) page. A CPEO contract must contain the exact name and Employer Identification Number (EIN) of the CPEO fulfilling the federal employment tax obligations covered by the contract.