Many European countries (the Schengen states) require that your passport be valid for at least three months beyond your planned date of departure from the Schengen area.
As a general rule, passports must be valid for six months beyond the date the traveler will exit the United States. However, the United States has signed agreements with a number of countries to waive this requirement.
Passport Validity for FranceEntry into France for short-term tourism (90 days) or business requires that your passport be valid for at least three months beyond your intended date of departure from the Schengen Area.
Passports must be valid for six months beyond your entry date. You will be denied entry into Turkey if there is not enough space for entry and exit stamps in your passport.
In normal circumstances, you can't travel with a passport that expires in less than six months. However, a country with an active agreement with your destination country may allow it. You may even enter with an expired passport in some countries as long as you still have the document with you.
U.S. nationals, including U.S. dual nationals, must use a U.S. passport to enter and leave the United States. U.S. dual nationals may also be required by the country of their foreign nationality to use that country's passport to enter and leave that country.
While Greek law requires three months of passport validity beyond the intended date of your departure, if you are transiting a country that requires six months of validity, you may not be permitted to continue your trip. We recommend that you have at least six months of validity to avoid any travel disruptions.
Be aware of passport expiration rules for your destinationSome countries and airlines will not allow a U.S. passport holder to enter if their passport expires in less than 6 months. Check your destination country's U.S. passport expiration rules on the Department of State's country information page.
Have at least six-month's validity remaining on your passport whenever you travel abroad. Check the expiration date on your passport carefully before traveling to Europe ? especially children's passports, which are valid five years, not 10 years like those issued to U.S. citizens aged 16 and older.