When you pay tax on a sale
You pay tax if you sell within 5 years, counted from the end of the year in which you bought. A flat bought in 2023 can be sold tax-free from 1 January 2029. For an inheritance, the date the deceased acquired it counts.
The rate is 19% of income: the sale price minus selling costs, the purchase price and documented improvements. You declare it in a PIT-39 return by 30 April of the following year.
Housing relief
If within 3 years from the end of the year of sale you spend the proceeds on your own housing, for example buying another flat or repaying a housing loan, that part of the income is exempt.