If HR want to know about the calculation of personal income tax and Income tax deductions. I'm welcome and I can provide knowledge with HR. About this, but HR didn't ask me to teach them to know, and HR told me that my must responsible to take it personal income tax. And I am welcome. But ask me do everything payroll better. Because in the future if HR doesn't know it ทำให้เค้า don't pay income tax system.