These are the country codes in Zone 4.
- +40 – Romania
- +41 – Switzerland
- +420 – Czech Republic
- +421 – Slovakia
- +423 – Liechtenstein
- +43 – Austria
- +44 – United Kingdom
- +45 – Denmark
- +46 – Sweden
- +47 – Norway, Svalbard & Jan Mayen
- +48 – Poland
- +49 – Germany