What is the time limit for the patent confidentiality review request?

Paragraph 1 of Article 20 of the Patent Law stipulates that any unit or individual who applies to a foreign country for a patent for invention or utility model completed in China shall file a confidentiality review with the Patent Office in advance. Upon receipt of the request for confidentiality review of foreign patents, the Patent Office will immediately start the review procedure and issue the Notice of Opinions on Confidentiality Review of Foreign Patents in time, informing the applicant of three conclusions, namely, "the document does not meet the requirements, and it is deemed that the request for confidentiality review has not been submitted", "it is obviously unnecessary to keep secrets, so you can apply for a patent in a foreign country" and "further confidentiality review is needed, and the application for a patent in a foreign country is suspended". After the successful submission of the confidentiality review, if the notification of the confidentiality review is not received within 4 months from the date of submission of the request, and the confidentiality decision is not received within 6 months from the date of submission of the request, you can apply for a patent for invention or utility model abroad or submit an international patent application to the relevant foreign institutions.