I appreciate that this reply is not timely in relation to the original query but I found it so difficult to find information on Polish Tax and Rental Income that I will post it as a guide for anyone who is looking for a rough guide.
I have to stress the information given to me is a couple of years old but it is my understanding that there is no significant change.
You are allowed depreciation of 1.5% on the total of the following:
Cost of the apartment
Notary/ (legal) Fees relating to the purchase
Cost of Fixtures and Fittings
Any Pre Rental Mortgage Interest incurred
Any Bank Charges for providing Mortgage
Expenses that are 100% Allowable against Rental Income:
Mortgage Interest
Service Charges
Bank Charges
Advertising and Letting Charges
Tax is payable monthly, in arrears, by c. 20th of the following month. In December you guesstimate and pay in advance (tax year ends 31 December)
Calculation of Tax Payable
Add Rental Income Year to Date
Less Depreciation
Less Allowable Expense
Equals Taxable Amount
The first 3,091 PLN of the Taxable amount (assuming no other income) is tax free. The balance is taxable at 18.0% up to c.85k PLN at which point the marginal rate is 32%.