European Patent Convention - Enforcement and Validity - Validity

Validity

Validity is also remitted largely to national law and national courts. Article 138(1) EPC limits the application of national law to only the following grounds of invalidity, and specifies that the standards for each ground are those of national law:

• if the subject-matter of the European patent is not patentable within the terms of Articles 52 to 57 EPC (see "Substantive patent law" section above);
• if the disclosure does not permit the invention to be carried out by a person skilled in the art;
• if amendments have been made such that the subject-matter extends beyond the content of the application as filed;
• if the claims have been broadened post-grant, e.g. in opposition proceedings;
• an improper proprietor—in some jurisdictions, only the person pretending to be entitled to the European patent can raise this specific ground, so that the resulting nullity of the patent may be relative to some persons only—.

A national court may partially invalidate a European patent in a Contracting State, e.g., by revoking only some claims, or by permitting amendment to the claims, the description or the drawings, as allowed by national law.

A European patent is also non-unitary in that it may be revoked in one Contracting State while maintained in another. However, a national court in one Contracting State may not revoke a European patent in another Contracting State.