Calculation of Employment Tax in the Payroll 
In the SAP R/3 system, you calculate employment tax deductions and payments in the payroll process for a specific tax period.
If you have defined an applied deduction rate in the infotype
Tax data (0062), the system will take this as the employment tax deduction rate. Otherwise, if you have not defined an applied deduction rate, the system specifies a deduction rate according to the regional code and the payee key and subkey (calculated rate).The calculation of the employment tax deduction and payments includes
retroactive accounting and payments in kind through the assignment of the value corresponding to the EST00 function within the tax calculation subschema.The correct processing of employment tax deductions and payments in the payroll process is linked to the system check of data entered in the infotype 'Tax data' (0062).
Settings in the Implementation Guide
So that the tax calculation can be integrated correctly in the payroll process, in the personnel management Implementation Guide you must first have entered the necessary settings corresponding to the master data of the employment tax calculation management. Equally in the Payroll Implementation Guide all the setting relating to the calculation of employment tax in the payroll itself should have been carried out: You can make these settings in Payroll ® Employment Tax:
Description of the process
Processing of data for the employment tax deduction and payment calculation is specified in the main payroll schema ED00 by the subschema
EST0. This subschema processes the corresponding calculation rules and functions. In general, the employment tax deduction (IRPF) calculation process follows the following steps:See also:
The Spanish payroll schema