Before which authority:
Before the local court (Amtsgericht) or the regional court (Landgericht), depending on the value of the dispute.
According to which procedure (state the applicable rules):
There is no special remedy against the probative value of an authentic instrument: on the one hand, one of the parties can challenge the probative value of an instrument in any proceedings in which the instrument is presented as evidence. However, it is also possible to challenge an authentic instrument in proceedings intended solely for this purpose by way of a remedy seeking declaratory relief (« Feststellungsklage » provided for in Art. 256 of the German Code of Civil Procedure).
Within what timeframe:
As there is no special remedy (see above), no particular time limit must be respected, other than the time limits for proceedings.
