Foreigners from European Union and European Economic Area
Citizens of Member States of European Union, as well as citizens of Member States of EEA (i.e. Norway, Iceland or Lichtenstein) are allowed to set up and carry out a business on the territory of the Republic of Poland on the same terms as Polish citizens.
Citizens of such countries are allowed to set up a sole tradership in Poland (i.e. one subjected to registration in CEIDG) or to set up (as a shareholder or partner) any company or partnership.
If such foreigners already operate a company in their respective country of origin, they can freely set up a branch of an representative office of their company.
Therefor scope of freedom of European citizens is rather wide.
Foreigners from third countries (i.e. from outside of EU and EEA)
The matters are different if it comes to citizens of so called third countries (you have to also remember that the Great Britain is considered a third country after Brexit).
Citizens of third countries (i.e. from outside of EU and EEA) have a right to freely set up a company in Poland (i.e. limited liability company, simplified joint-stock company and joint-stock company) as well as limited partnership and partnership limited by stock. Therefore they are prohibited from running a business in a form of general partnership or limited liability partnership.
However, if foreigners from third countries wish to set up and carry out a sole tradership in Poland, they have to possess a residence title enabling them to do so. Act of 6 March 2018 on the principles of participation of foreign entrepreneurs and other foreign persons in economic turnover on the territory of the Republic of Poland provides for a range of cases where the residence title (permanent or temporary residence) entitles to set up and carry out a sole tradership in Poland. It occurs, for instance, when a foreigner possesses a permanent residence permit or if they possess a temporary residence permit and at the same time are married to a Polish citizen who resides on the territory of Republic of Poland.
Similar to foreigners from European Union – foreigners from third countries, in the event that they operate a company in their country of origin, are permitted to set up a branch of a Company in Poland (unless ratified international agreement state otherwise) as well as a representative office of such a company.