 banking or authority contacts).Strictly speaking, it is not necessary for an EU, EEA or Swiss citizen to possess a valid travel document (such as a national identity card or passport) to enjoy the right of free movement in the EU, EEA and Switzerland.In theory, if an EU, EEA or Swiss citizen can prove his/her nationality by 'any other means' (e.g., by presenting an expired national identity card or passport, or a citizenship certificate), he/she must be permitted to enter and reside in the EU, EEA and Switzerland without a visa.