Dual filings and where to find them

22 November 2021

In China, applicants may file for a utility model and a patent application on the same day. These "dual filings" will share the same priority date and cover the same technical content.

In doing so, applicants receive fast-lane protection for the utility model (maximum 10 years). However, they must abandon the utility model upon notification of the grant of the patent if they want the benefit of a patent for a longer period of protection (maximum 20 years).


Figure 1. Example first page of a published utility model

"(ESM)" on the first page of the utility model is an indicator that a patent covering the same invention has been filed; there is no such indicator on the patent application.

Do dual filings belong to the same patent family?

In short, no. Patent families are based on priorities and dual filings do not share any priority. As such, they will only belong to the same patent family if they are manually merged into what is known as a technical family. And it's important to note that this is only done if requested or if the examiner discovers the two filings during the search phase. Due to the high numbers of dual filings - between 10 and 20% of all applications in China - a systematic search or approach is not feasible.

The utility model CN204947954U - Independent solar energy or wind power generation electric capacity cushion system of converging and the patent application CN105186970A - Capacitive buffering and collecting system for independent solar or wind power generation have been merged into one family.

Finding the related document when it's not in the patent family

In Espacenet or GPI, you can retrieve the related document by entering the applicant's name and filtering by the earliest priority date.


Figure 2. Example Espacenet search combining applicant name and earliest priority date in Filters

Alternatively, you can find dual filings in the citations of a search report, i.e. in the Global Dossier service. The category (Type) "R" assigned to citations in the search report refers to patent applications or utility models filed on the same day and relating to the same invention.


Figure 3. Example search report citing a document of Type "R"

Challenges when searching

As we've already mentioned, dual filings always share the same priority date and technical content but the title and applicant name can differ. Take a look at the following dual filing examples in Espacenet. You can see that the inventor's name is the same in each one but the title and the applicant's name are different:

Utility model CN206742814U - Cable ice removing running gear of the patent CN107294038A - Cable de-icing running gear.

Whichever option you choose to search for a related filing, remember that the search might not always be straightforward and there may be challenges on the way.

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