Quick help

Help

Application number

The application number is the number assigned to a patent application when it is filed.

The application number for the majority of countries is made up of a country code (two letters), the year of filing (four digits), and a serial number (variable, maximum seven digits). A serial number having fewer than seven digits may be rounded up to seven digits by adding zeros (e.g. GB19950008026). Alternatively, the zeros may be omitted entirely (e.g. GB19958026).


EP application numbers can be entered with either two or four digits for the year : e.g. EP07109822 or EP2007109822 are allowed.


There are twelve countries/organisations which use another format, namely Australia, Germany, China, Brazil, Ukraine, Gulf Council, Hungary, India, Italy, Mexico, OAPI and the WIPO.

In this case, the application number is made up of :


  • a country code (two letters)
  • the year of filing (four digits)
  • "other" information (one or two characters)
  • a numerical digit (five to six)

There is a fixed length of 13 characters, excluding the kind code and where appropriate the fixed length is achieved by inserting leading zeroes.


The format for the WO (PCT) application number in Espacenet consists of the country code WO followed by the year of filing (4 digits), the country code of the country where the application was filed (two characters) and a 5-digit serial number adding up to a fixed length of 13 characters.

To find, for example, PCT application PCT/IB2007/51010, you will have to type in WO2007IB51010. If you are searching for application number PCT/MX2007/000062, you will have to enter WO2007MX00062 (i.e. remove the leading zero).


Kind codes A, B or C should not be entered as these types of documents are automatically retrieved. However, in some cases you may need to enter the kind code (D-Z) directly after the country code and the serial number in order to view the patent document (e.g. KR19910000410U).


To retrieve all the documents having a particular country code in combination with other entries (dates, etc.), all you have to do is enter the country code (e.g. GB) in the application number field in combination with a date in the publication date field.


In case you cannot retrieve the application number you are looking for, please contact the Espacenet helpdesk at espacenet@epo.org.


For more information on patent searching, see the following pages: