Tax calculation filing jointly and having 2 kids - Poland

Can you please help me to understand taxation in Poland.
1) Details about non taxable income
2) Details about tax credit
3) Does NFZ gets credited from total tax?
4) Is below calculator correct?
calculla.com/polish_annual_earnings_calculator

1) Almost all income is taxable, with the exception of some subsidies such as for installing solar panels.
2) There are some tax credits, but they're so low as to not worth thinking about.
3) Yes, NFZ is taken from the gross salary, not net.
4) Yes.

@delphiandomine
Thanks for information.

Can you please help me to understand some more points:
1) Is there any benefit of filing jointly?
The calculator is showing a big difference in final tax while choosing "Joint filing" option.
e.g. suppose gross is 15000 PLN, calculator show "Tax difference to return14995.00".
Will 14995.00 PLN be refunded back while filing tax?

2) Is there any benefit in tax for kids?

1. Yes, but only if one partner does not work or has any other income.
2. Yes, you can claim tax allowance for children on your tax return. You need to find out how much, but you can deduct so much for each child.

@terri
Thanks for information.
It means calculator is showing correct calculation for joint filing.
As per calculator maximum part of the PIT will be refunded back if filing jointly (in case partner doesn't have income)
Can you please confirm if calculator is showing correct data?

No, not quite like that. The main benefit from joint declarations is that you combine the tax base, so you only pay 32% once you reach 171,056zł together.

@terri and @ delphiandomine Thanks for information.
If calculator is showing correct calculation for joint filing, then maximum part of the PIT will be refunded back if filing jointly (in case partner doesn't have income).

Could you please confirm if this is correct understanding?

No, it's more complicated than that. If you file joint tax returns, then you pay 18% of everything above ~6000PLN/year, and 32% above 171,056PLN/year. There are some tax credits that will raise the amount slightly, but nothing worth talking about.

If you pay more than that during the year in advance tax payments, then you'll be refunded after submitting a tax return.

The calculator on calculla is not correct. It overestimates the benefit of joint declaration. Better use bankier.pl/narzedzia/kalkulator-placowy

I have an add on question, My wife has been offered 5750 PLN gross, and almost all the tax calculators say her salary net will be 4070, beats me, as I understood if one's salary is lower than 85,520 pln, she falls in 18% slab and not 32%, can someone please clarify

net salary = gross salary - pension insurance - disability insurance - health insurance - income tax, where the last one is calculated on taxable income only, not on the gross income

Exactly.

Indian, google for graphics pasek wypłaty - pay slip and you will see the difference between gross (brutto) and net.

Just out of interest, I looked on the calculations of salary of 5,750 pln per month gross, the net would be 4,006 pln per month.