Separate and Non-separate Payment in Kind 
The SAP payroll allows inclusion of separate payments in kind (the employment tax deduction (IRPF) payment is responsibility of the employee) and non-separate payments in kind (the deduction payment is responsibility of the company).
Described below are the processes for both system settings.
A previous requirement is that the payment in kind wage types are assigned the unequivocal definition of ‘separate’ or ‘non-separate’ payment-in-kind type. An example of the former case is the model wage type PE01 (Payt in kind: vehicles) and an example of the latter, the wage type PE04 (Payt in kind: vehicles NR).
Process for separate payment of employment tax:
Model wage type PE01 (Payt in kind: vehicles) cumulates both to wage type /107 (Payt-in-kind basis) and to /171 (Payt-in-kind basis vehicles). During the payroll process wage type /402 (Employment tax deduction payment) is generated, and the employment tax (IRPF) percentage corresponding to wage type /107 is applied. Likewise, wage type /431 (Empl.tax ded. vehicles) is applied with wage type /171 as basis.
Take into account that each separate payment in kind must cumulate to wage type /107 (Payt-in-kind basis), but depending on the type of payment in kind (co. car, loan, etc.) your customer wage type must cumulate to a specific /17x wage type. You use this information in the Deduction Certificate generated once a year for the employees. Depending on the value the field 'Payment key' in the infotype
'Tax data' (0062) , the system also generates one of the pairs of wage types formed by taxable basis wage types and wage types for model 190: /156, /416 or /158, /418 or /160, /421 or /162, /423, with the aim of including payments in kind in the Annual statement of employment tax (IRPF) deductions and payments (model 190).Wage type /402 (Employment tax ded. payt) takes value 4 in processing class 5; That is, it is deducted from the employee net pay.
Process for non-separate payment of employment tax:
Model wage type PE04 (Payt in kind: vehicles NR) cumulates both to wage type /108 (Payt-in-kind basis NR) and to /141 (Payt-in-kind basis vehicles NR). During the payroll process wage type /403 (Employment tax deduction payment NR) is generated, and the employment tax (IRPF) percentage corresponding to wage type /108 is applied. Likewise, wage type /43A (Empl.tax ded. vehicles NR) is applied with wage type /171 as basis.
Take into account that each separate payment in kind must cumulate to wage type /108 (Payt-in-kind basis), but depending on the type of payment in kind (co. car, loan, etc.) your customer wage type must cumulate to a specific /14x wage type. You use this information in the Deduction Certificate generated once a year for the employees. Depending on the value the field 'Payment key' in the infotype
'Tax data' (0062) , the system also generates one of the pairs of wage types formed by taxable basis wage types and wage types for model 190: /15F, /41F or /15H, /41H or /16J, /42J or /16L, /42L, with the aim of including payments in kind in the Annual statement of employment tax (IRPF) deductions and payments (model 190).Wage type /403 (Employment tax ded. payt NR) takes value 0 processing class 5; That is, it is deducted from the employee net pay.

If, in your company, you want payments in kind to cumulate to the Social Insurance contribution bases (/102 and /105), you must configure your customer wage types /402 and /403 in accordance with your own interpretation of current legislation. Cumulation is automatically carried out in function EST00 in accordance with the default settings.