For domestic flights within Greece, the presentation of an ID card (for children over 12 years old), or a passport, or a health booklet with a photo, or a birth certificate is sufficient.
If a child is travelling with only one parent, it is recommended to present a consent declaration (certified by a public authority such as a Citizens’ Service Centre (KEP) or via gov.gr) confirming the other parent’s consent to the trip.
If the child is accompanied by an adult other than the parents, it is recommended to present a certified consent declaration signed by one or both parents (or the legal guardian(s)), explicitly stating the relationship between the accompanying adult and the child and granting permission for travel.
For international flights, such declarations (or other documents, which should be in English) may be mandatory. We therefore recommend contacting the relevant authorities of the departure and arrival countries, as travel documents are the passenger’s responsibility.