Corporate income tax

Foreign entities starting a business in Poland do not have to opt for setting up a local company. After all, running a business in Poland may take on different forms: you can set up a branch, hire local employees or merely partly transfer some processes (e.g., establish a warehouse or a design office). Sometimes foreign entrepreneurs decide to enter into close cooperation with an independent entrepreneur operating in Poland.

As it usually happens with changes introduced into the tax law, on the quiet and through the back door a significant change is made as for the moment of including the effects of the issued (or received) invoice correction in corporate income tax/personal income tax calculation. Why is this moment so crucial?