4.1 Formal requirements
4.1.2States for which European patent applications may be filed
4.1.002When filing a European patent application all the contracting states for which the EPC has already entered into force on the date of filing are deemed to be designated (see point 2.2.001 for the list of contracting states).
Switzerland and Liechtenstein may only be designated jointly.
4.1.003In addition, European patent applications and patents may be extended to states not party to the EPC. At present, the only extension state is Bosnia and Herzegovina (see point 2.5.001).
4.1.004European patent applications and patents can be validated in the countries in which a validation agreement entered into force on or before the date of filing of the European patent application (see point 2.5.001).
References in this Guide to the designation of contracting states also apply to extension to and validation in non-contracting states, unless explicitly stated otherwise.
As regards extension and validation states, the extension and all validations are deemed to be requested upon filing of the application, but you need to confirm the request for extension/validation by paying the extension/validation fee for each state to or in which you wish to extend or validate protection.
GL A‑III, 12