Why do I need official consent?
If you plan to send your child on holiday abroad in the care of grandparents, friends or even one of the parents, it is important to prepare an official consent signed by the legal guardians of the child (usually parents). Such consent is required in many countries, e.g. in the United States, Canada, Switzerland or in the European Union. Within the Schengen area*, such formalities may seem unnecessary, but the lack of the obligation to give consent to a country's consensus does not mean that it is not legally required.
An important point is consent to “make all decisions regarding medical care by the person under whose care our child will remain during this stay". In the event of any
accident, lack of such consent may lead to problems with the procedure or information about the child's health.
CONSENT IN POLAND
How to properly prepare consent?
Good to remember;
Consent of one parent only;
Under Polish law, a parent can take a child abroad without the consent of the other parent, if:
CONSENT IN SPAIN
In Spain, the requirement is to sign an official model of consent available at any Gaurdia Civil or Policia Nacional station. The form must be signed on the spot in the presence of officers by the legal guardians of the child.
* According to Annex VII, Regulation (EC) No 562/2006 of the European Parliament and of the Council of 15 March 2006 establishing a Community Code on the rules governing the movement of persons across borders (Schengen Borders Code)
6. Minors
6.1. Border guards shall pay particular attention to minors, whether travelling accompanied or unaccompanied. Minors crossing an external border shall be subject to the same checks on entry and exit as adults, as provided for in this Regulation.
6.2. 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.
6.3. 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.
[Https://eur-lex.europa.eu/legal-content/PL/ALL/?uri=celex%3A32006R0562]