3.4 Signature of the notice of opposition 

The notice of opposition must be signed by the person responsible, i.e. the opponent or, where appropriate, the representative (see also D‑IV, 1.2.1(ii) and A‑VIII, 1).

Initials or other abbreviated forms will not be accepted as a signature.

Where the notice of opposition is filed in electronic form, the signature may take the form of a facsimile signature or a text string signature (i.e. a type-written signature that is preceded and followed by a forward slash (/); see OJ EPO 2025, A52). Where EPO Online Filing is used, the signature may also take the form of an enhanced electronic signature (see OJ EPO 2023, A48).

If the signature is omitted, the formalities officer must invite the party, or where appropriate the representative, to affix their signature within a time limit to be laid down by the formalities officer. If signed in due time, the document retains its original date of receipt; otherwise, it is deemed not to have been received (see D‑IV, 1.2.1(ii) and D-IV, 1.4.1).