Applying Tax Exemption based on condition

How to apply Tax Exemption based on condition?
I need to apply this condition
Exemption Condition: 1/3rd of Gross Salary or (Max Limit) Tk. 4,50,000.00 whichever is lower

How to apply this?

Are you talking about Employee Tax Exemption Declaration doctype?

If so, what I understand is that, the number in “Delcared Amount” field is the final amount after all kinds of calculation outside of the system.

In my very case, we also face the same requirement as you, and we end up develop another tab that allow user to input data before calculation and keep it in “Input Amount” field. Then some logic will calculate and keep it in the “Delared Amount” field (standard).

My document finally looks like this,

After saved, the calculation logic (which is quite hard coded as per country regulation) will reset the Tax Exemption Declaration table like this,

So, my answer is, you might need some customization for your country specific tax exemption requirement.