If no evidence of legal succession is produced, the mere declaration by a company designated as legal successor to the original opponent that it is the original opponent's legal successor is not sufficient to substantiate the transfer of the status of opponent and of party to the appeal proceedings (T 670/95).

In T 261/03 of 24 November 2005 date: 2005-11-24 the board of appeal considered what kind of evidence was required to establish a valid transfer. The board made a parallel to the requirements of R. 20 EPC 1973 and noted that it was not aware of any appeal decision that had held that the documents to be submitted according to this provision have to prove the alleged transfer "up to the hilt". Such a yardstick of full and absolute proof would indeed be overly strict since in many situations documentary evidence alone could then hardly suffice. As the wording of R. 20(1) EPC 1973 suggested, something less was required. The board took the view that the requirements of R. 20 EPC 1973 were complied with if the documents submitted were such as to render it credible to the competent organ of the EPO, evaluating the documents in a reasonable way and in the light of all the circumstances, that the alleged facts are true. The mere fact that another document might have been a more direct piece of evidence than the one submitted by the appellant does not invalidate the proof actually offered (see T 273/02, applied in T 1178/04).

In T 1513/12 the board refused a request for a transfer of opponent status because, although the filed extracts from a commercial register showed there had been a spin-off, they did not contain any evidence of a transfer. In particular, no extracts from the spin-off agreement or from the agreements negotiated in this connection, which could have proved the transfer more conclusively, had been filed.

In T 219/15 the board refused the request for transfer of the opponent status. The appellant had provided the purchase agreement, but that agreement did not demonstrate that the relevant business assets, i.e. the opposition proceedings relating to the patent in suit, were sold to the other company.

In T 2016/12 the board rejected the transfer of a specific part of the original appellant's (ATech Ltd) business assets to the purported transferee (AES AG). The board had requested the submission of the contracts concluded between the legal entities involved in the merger; the opponent replied, however, that such contracts could not be provided for reasons of confidentiality. Other evidence presented was not conclusive. Furthermore, the board considered that if a transfer was not unequivocally proven, the original party to the proceedings would normally continue to be considered as the appellant. However, in the case in issue, ATech Ltd (the original party) allegedly continued to exist under its new name of GETech GmbH. However, from the two extracts of the commercial register concerning the business GETech GmbH, it was apparent that some assets had been transferred according to a separation plan to yet another company. The party provided no details as to this split or the business assets involved. The evidence indicated that GETech GmbH did not become the universal successor to that party through a complete acquisition of the entire business of the original party and a successive simple change of name. Therefore, it also could not be concluded that GETech GmbH was a party to the proceedings. Under these circumstances, the board could not reliably establish ownership of the business assets to which the opposition and appeal belonged. Consequently the board could not continue the proceedings, which therefore had to be terminated.