On the basis of Polish law, in a situation where the border is crossed by a minor who travels alone and has their own identity card (e.g. across the countries within the Schengen area) or a travel document (passport) at the external borders, the child or a guardian with whom the child travels (e.g. the child’s parent when travelling with only one of them) is not legally required to have additional documents confirming the travel circumstances or the circumstances in which the child has been placed in the care of another person.

Special rules for border controls on minors result from Regulation (EU) 2016/399 of the European Parliament and of the Council of 9 March 2016 on a Union Code on the rules governing the movement of persons across borders (Schengen Borders Code), set out in point 6 of Annex VII:

• minors crossing an external border shall be subject to the same checks on entry and exit as adults, as provided for in the above Regulation.
• In the case of accompanied minors, the border guard shall check that the persons accompanying minors have parental care over them, especially where minors are accompanied by only one adult and there are serious grounds for suspecting that they may have been unlawfully removed from the custody of the person(s) legally exercising parental care over them In the latter case, the border guard shall carry out a further investigation in order to detect any inconsistencies or contradictions in the information given.
• In the case of minors travelling unaccompanied, border guards shall ensure, by means of thorough checks on travel documents and supporting documents, that the minors do not leave the territory against the wishes of the person(s) having parental care over them.
• Member States shall nominate national contact points for consultation on minors. The list of national contact points is made available to the Member States by the European Commission. Where there is doubt as to any of the above circumstances, border guards shall make use of the list of national contact points for consultation on minors.

Once their travel document expires, the foreign national should visit their diplomatic mission to obtain a document authorising their return to the country of origin.

It should be noted that the European Union has concluded agreements on the facilitation of the issuance of visas with certain third countries which allow foreign nationals who have lost their identity documents, or from whom these documents have been stolen while staying in the territory of the Member States, to leave that territory on the basis of valid identity documents entitling them to cross the border, issued by diplomatic missions or consular posts of the Member States, without any visa or other authorisation.

This provision is included in the agreements on the facilitation of the issuance of visas that the European Community/European Union has concluded with the following third countries: the Russian Federation, the Republic of Albania, Bosnia and Herzegovina, the Republic of Montenegro, the Former Yugoslav Republic of Macedonia, the Republic of Serbia, Republic of Moldova, Republic of Azerbaijan, Georgia, Ukraine, the Republic of Armenia and the Republic of Belarus.

In other cases (third-country nationals with which the aforementioned agreements providing for the above solution have not been concluded), as a rule, proceedings are initiated to oblige the foreign national to return. Moreover, in accordance with the Foreigners Act of 12 December 2013, residence in the territory of the Republic of Poland by a foreign national who is not authorised to stay on that territory is an offence punishable by a fine.