Regulations under the PCT
Rule 93
Keeping of Records and Files
Each receiving Office shall keep the records relating to each international application or purported international application, including the home copy, for at least 10 years from the international filing date or, where no international filing date is accorded, from the date of receipt.
(a) The International Bureau shall keep the file, including the record copy, of any international application for at least 30 years from the date of receipt of the record copy.
(b) The basic records of the International Bureau shall be kept indefinitely.
93.3 The International Searching and Preliminary Examining Authorities
Each International Searching Authority and each International Preliminary Examining Authority shall keep the file of each international application it receives for at least 10 years from the international filing date.
For the purposes of this Rule, records, copies and files may be kept as photographic, electronic or other reproductions, provided that the reproductions are such that the obligations to keep records, copies and files under Rules 93.1 to 93.3 are met.