Andorra, Liechtenstein, Monaco, San Marino, and the Vatican City remain outside the Union, because the EU has not been designed with microstates in mind.
People Also Ask
Why has Monaco not been absorbed by France? The political reason is the Franco-Monegasque treaty of 1861, which guaranteed the national sovereignty of the Prinipality of Monaco.
In order to become a resident, applicants must rent or purchase a property here, and deposit and maintain at least 500,000 euros into a bank registered in Monaco.