Dual filing of patents and utility models is possible under Article 9 of the Chinese Patent Law. The applications must be filed by the same applicant on the same day and the utility model must be abandoned upon notification of grant of patent. Previously, it was difficult to locate information on dual filing cases, as there was no link in the Chinese databases between the patent application and the corresponding utility model filed on the same day.
This information can now be searched in the CNIPR database when using the number search option. Currently, this information can be retrieved in the Chinese language version, which offers a number of features free-of-charge. For example, when the user searches with a patent application number, the corresponding utility model application will also be displayed in the bibliographic information. More advanced search and filtering options of dual filings, however, are only possible with a payable subscription.
A new step-by-step guide for searching this information in Chinese language can be found in the "China - Searching in databases" section of the EPO's virtual helpdesk on Asian patent information.