All employers (including multifirm employers) are required to report on form W-3 to
            IRS and SSA to transmit the form(s) W-2 wage data for their employers.
         
         Multifirm employers or those with several subsidiaries in various geographic locations
            found it difficult to use one EIN. The “Establishment Reporting Plan” (ERP) was developed in order to obtain a breakdown of multiunit employment and wages
            that are allocated to various industries and geographical areas to simplify reporting
            for the “parent” company.
         
         The ERP involves:
         
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                     Grouping employee names by “establishment” within the consolidated wage and tax statement; 
 
 
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                     Identifying each group by an employer establishment or reporting unit number; 
 
 
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                  • 
                     A separate W-3 may be used for each establishment, or all of the establishments may
                        report under one W-3 arranged in establishment order. Each reporting unit uses a separate
                        wage and tax reporting statement;
                      
 
 
Prior to 01/01/87, SSA assigned Payroll Record Unit Numbers to State and local subdivisions
            or coverage groups that had more that one payroll record unit.
         
         Not all multifirm employers or employers who file multiple W3s use establishment numbers.
            Establishment numbers are not required by either SSA or IRS. However if the employer
            reports under an ERP, the establishment number is needed in order for OCRO to scout
            wages.