R. 76(2)(a) EPC (former R. 55(a) EPC 1973) provides that the notice of opposition must contain the name, the address and the state where the opponent's residence or principal place of business is located. R. 41(2)(c) EPC (former R. 26(2)(c) EPC 1973) deals with the precise particulars by which such identity needs to be established. If the identity of an opponent is not established before expiry of the period allowed for filing an opposition, the opposition is inadmissible (T 25/85, OJ 1986, 81). This defect cannot be remedied (T 590/94).
Further deficiencies such as a wrong postal code or lack of signature may be subsumed under R. 76(2)(a) and R. 50(3) EPC, respectively, and can thus be remedied within a time limit set by the opposition division in accordance with R. 77(2) EPC, the opposition division has to set a time limit for the remedy of these deficiencies. The opposition division has also the power to extend this time limit or to set a new time limit whenever this was deemed appropriate (T 1632/06).
In T 870/92 the board emphasised that, when indicating a legal entity, failure to use its exact official designation (R. 41(2)(c) and 86 EPC; former R. 26(2)(c) EPC and R. 61a EPC 1973) did not necessarily mean that the opposition was inadmissible. An incorrect designation which nevertheless sufficed to indicate the party's identity had to be distinguished from the absence of such information. Errors in a designation could be corrected at any time (R. 139, first sentence, EPC; former R. 88, first sentence, EPC 1973; see also T 828/98).
A natural or legal person filing an opposition must be identifiable at the latest at the end of the opposition period. In principle, the use of an abbreviation instead of the full name of a legal entity does not render an opposition inadmissible as long as the party’s identity can be established. In T 1034/08, the board had no reasonable doubt that the abbreviation GSK stood for GlaxoSmithKline with regard to the identity of the Belgium-based opponent GSK Biologicals. Given that Belgian Company Law allows the co-existence of more than one company name and that GlaxoSmithKline Biologicals is the company's sole primary name, the board concluded that abbreviation GSK Biologicals did not constitute an incorrect designation of the opponent.
In T 1165/03 the board regarded an identity card or passport as the best evidence of identity but with the same proviso as applies to all evidence, i.e. that its value could be offset or even negated by other evidence. In this case, two different photocopy identity cards had been filed: the first had been sent to the opposition division and, although even less legible than the copy later faxed to the board, it was clearly not a copy of the same document as that shown in the fax and subsequently filed during the oral proceedings. The letter signed in the opponent's name said his name had only been used accidentally in relation to the proceedings and that he was more often at his work address than the home address shown on the identity card. However, there was no legible address on the earlier photocopy card on file. Moreover, the work address in the letter was not that shown on the second photocopy card filed with the board. The board therefore held that the identity card evidence was inherently unreliable and inconclusive.
Questioning the identity of an opponent is not enough to render the opposition inadmissible; to achieve that, cogent evidence must be put forward. In T 4/05 no such case was made. The appellant had not filed the excerpt from the commercial register which, according to its submissions during oral proceedings before the board, showed a different company name. This could therefore not be cited as evidence that the opponent's identity was unclear – as indeed the appellant acknowledged at the oral proceedings. The appellant's objection that two other companies were trading at the same address as the opponent also failed; this was merely an observation which could not affect the party status of an opponent who had been unambiguously identified.