Although documents are not checked when one crosses an internal Schengen border, it is still necessary for EU citizens (including Estonians) to carry a passport or ID card. Authorities (police, immigration officials) in Schengen states do have the right to check identification documents, if necessary.
A traveller must apply for a Schengen visa from a representative (i.e. embassy) of the primary country he/she will be travelling to. If a traveller will be visiting several Schengen states and does not know where his/her main destination will be, he/she must apply for a visa from the embassy of the country through which he/she will enter the Schengen area.
A citizen of a non-Schengen state or an individual of undetermined citizenship who has a residency permit in a Schengen state does not need a visa to travel to other Schengen states.
Estonian visas issued prior to Estonia’s accession to the Schengen area are only valid for travel to Estonia.
Schengen visas issued prior to Estonia’s accession to the Schengen area will be valid in Estonia as well after its accession.
A Schengen visa is not valid in French or Dutch overseas territories.
A Schengen visa is valid for travel to the Principality of Monaco.