From: Rabbi Moshe Sofer
To: Rabbi Meir
The Chasam Sofer rules that a pruzbul declaration written at home and sent by letter to a beis din is not itself valid, as it was not executed before a beis din; instead, the beis din must write a new pruzbul dated from when the letter was originally written, since a postdated pruzbul is invalid. He further argues that the requirement for a distinguished beis din applied only in Talmudic times when shemittas kesafim was observed, and that today any beis din is competent since the pruzbul merely removes the issur rather than overriding any monetary right. He also provides resolutions to the hermeneutical difficulties raised concerning klal u'frat u'klal and the exclusion of land from pidyon haben.
Source: Shu"t Chasam Sofer CM §113