12.1 General remarks 

At the applicant's request and on payment of the prescribed fee, European patent applications (direct or Euro-PCT) and thus patents can be extended to European states having an extension agreement with the EPO (extension states). The same applies to requests for validation in European or non-European states having a validation agreement (validation states).

The states for which such requests may currently be filed are listed below:

(i)extension may be requested for the following European state: 

The EPO's extension agreements with the Republic of Slovenia (entry into force: 1 March 1994), the Republic of Romania (15 October 1996), the Republic of Lithuania (5 July 1994), the Republic of Latvia (1 May 1995), the Republic of Croatia (1 April 2004), the Republic of North Macedonia (as the former Yugoslav Republic of Macedonia) (1 November 1997), Albania (1 February 1996), the Republic of Serbia (1 November 2004) and Montenegro (1 March 2010) terminated when these countries acceded to the EPC with effect from 1 December 2002, 1 March 2003, 1 December 2004, 1 July 2005, 1 January 2008, 1 January 2009, 1 May 2010, 1 October 2010 and 1 October 2022 respectively. However, the extension system continues to apply to all European and international applications filed prior to those dates and to all European patents granted in respect of such applications.

(ii)validation may be requested for the following states (OJ EPO 2015, A20, OJ EPO 2015, A85, OJ EPO 2017, A85, and OJ EPO 2018, A16, and OJ EPO 2023, A105):

Extension and validation agreements are bilateral international treaties concluded between the European Patent Organisation and an individual state. Within the territory of that state, the effects of a European patent application for which an extension or validation request has been filed, or of a European patent that has been validated in an extension or validation state, are based on national law. The provisions of the EPC, its Implementing Regulations and the Rules relating to Fees do not apply to the extension and validation systems unless and only to the extent that those provisions are referred to by the applicable national law. Thus, the EPC provisions concerning applicants' legal remedies and appeals do not apply in respect of any action taken by the EPO under the extension or validation procedure (see J 14/00, J 4/05 and J 22/10), e.g. where the extension or validation fee has not been paid within the applicable time limit indicated (A‑III, 12.2). Similarly, no different claims, description or drawings are acceptable in respect of extension or validation states (see H‑III, 4.4), as Rule 138 does not apply to the extension and validation systems.

A request for extension to or validation for the above-mentioned states is deemed made with any European patent application filed after entry into force and, in the case of the former, before termination of the respective extension agreements. This also applies to Euro-PCT applications, provided that the EPO has been designated for a European patent and the extension or validation state has been designated for a national patent in the international application. The request is deemed withdrawn if the extension or validation fee is not paid within the prescribed time limit (see A‑III, 12.2). It is by paying the extension or validation fee that the applicant decides to extend the application to an extension state or validate it in a validation state. The declaration in the appropriate section of the request for grant form (EPO Form 1001) or of EPO Form 1200 for entry into the European phase before the EPO where the applicant is asked to state whether they intend to pay the extension or validation fee is merely for information purposes and intended to assist in recording fee payments.

A request for extension or validation in respect of a divisional application (see A‑IV, 1) is deemed made only if the respective request is still effective in the parent application when the divisional application is filed.