Setting Up Irregular Income Tax Calculations

Global Payroll for Thailand provides several formulas that enable you to determine the calculation order of the three types of irregular income: withholding, gross up one cycle, and gross up all cycles. The formulas are:

TAX FM IR FACTOR1
This formula enables you to specify which type of irregular income tax is calculated first by assigning different values to the TAX VR CAL METHOD variable. You must use specific abbreviations for each of the different types of irregular income, as follows:
- WH is used to indicate the withholding irregular income tax calculation type.
- GA is used to indicate gross up all cycles irregular income tax calculation type.
- GO is used to indicate gross up one cycle irregular income tax calculation type.
Adding your own if-else clauses into this formula enables multiple groups of employees to use different initial tax calculation types.
TAX FM IR FACTOR2
This formula enables you to specify which type of irregular income tax calculation type is calculated second.
TAX FM IR FACTOR3
This formula enables you to specify which type of irregular income tax calculation type is calculated last.

Warning! Incorrectly configuring these three formulas can cause errors in the calculation of irregular income taxes. For example, if all three formulas contain the code:'WH' >> TAX VR CAL METHOD, then the withholding irregular tax is calculated three times, while the other types of irregular taxes are not calculated at all.

If all employees in your company use the same calculation order, these three formulas can be very simple, each formula just has one line: 'WH'/'GA'/'GO' >> TAX VR CAL METHOD.

If the irregular income tax type calculation order is different for each employee, then these formulas will be very complex.

For example, assume that your organization has several pay groups that require a different order for the three tax calculation types for irregular income. The following table describes :

Pay Group	First Tax Calculation Type	Second Tax Calculation Type	Third Tax Calculation Type
Pay Group A or 'PGA'	Gross Up All Cycles	Gross Up One Cycle	Withholding
Pay Group B or 'PGB'	Gross Up One Cycle	Withholding	Gross Up All Cycles
Pay Group C or 'PGC'	Withholding	Gross Up All Cycles	Gross Up One Cycle
All Other Pay Groups	Gross Up All Cycles	Withholding	Gross Up One Cycle

So employees in Pay Group A use the gross up all cycles tax calculation type first, while employees in Pay Group B use the gross up one cycle type first, and employees in Pay Group C use the withholding tax calculation type first.

To accommodate this combination of tax calculation sequences, modify the three calculation order formulas as shown in the following table:

Contents of TAX FM IR FACTOR1	Contents of TAX FM IR FACTOR2	Contents of TAX FM IR FACTOR3
`'GA' >> TAX VR CAL METHOD If GP PAYGROOUP = 'PGB' Then 'GO' >> TAX VR CAL METHOD Exit Endif IF GP PAYGROUP = 'PGC' Then 'WH' >> TAX VR CAL METHOD Exit Endif`	`'WH' >> TAX VR CAL METHOD If GP PAYGROOUP = 'PGA' Then 'GO' >> TAX VR CAL METHOD Exit Endif IF GP PAYGROUP = 'PGC' Then 'GA' >> TAX VR CAL METHOD Exit Endif`	`'GO' >> TAX VR CAL METHOD If GP PAYGROOUP = 'PGA' Then 'WH' >> TAX VR CAL METHOD Exit Endif IF GP PAYGROUP = 'PGB' Then 'GA' >> TAX VR CAL METHOD Exit Endif`

Contents of TAX FM IR FACTOR1

Contents of TAX FM IR FACTOR2

Contents of TAX FM IR FACTOR3

'GA' >> TAX VR CAL METHOD
If GP PAYGROOUP = 'PGB'
 Then
	'GO' >> TAX VR CAL METHOD
	Exit
Endif
IF GP PAYGROUP = 'PGC'
 Then
	'WH' >> TAX VR CAL METHOD
	Exit
Endif

'WH' >> TAX VR CAL METHOD
If GP PAYGROOUP = 'PGA'
 Then
	'GO' >> TAX VR CAL METHOD
	Exit
Endif
IF GP PAYGROUP = 'PGC'
 Then
	'GA' >> TAX VR CAL METHOD
	Exit
Endif

'GO' >> TAX VR CAL METHOD
If GP PAYGROOUP = 'PGA'
 Then
	'WH' >> TAX VR CAL METHOD
	Exit
Endif
IF GP PAYGROUP = 'PGB'
 Then
	'GA' >> TAX VR CAL METHOD
	Exit
Endif