The application number is the number assigned to a patent application when it is filed.
All application numbers of all countries are standardised to one format, irrespective of the way in which they are printed on the patent documents. For the majority of countries, application numbers in Espacenet are made up of the country code(two letters), the year of filing (four digits), and a serial number (variable, maximum seven digits).
There is a fixed length of 13 characters in Espacenet, excluding the kind code. Where necessary, the fixed length is achieved by inserting leading zeros.
There are twelve countries/organisations which use a different format. These are Australia, Germany, China, Brazil, Ukraine, Gulf Council, Hungary, India, Italy, Mexico, OAPI and WIPO. They use application numbers made up of:
- a country code (two letters)
- the year of filing (four digits)
- "other" information (one or two characters)
- a serial number (five or six digits)
By way of exception, more recent numbers for Germany and United States have 14 characters.
EP application numbers can be entered in Espacenet with either two or four digits for the year. Both EP07109822 and EP2007109822 are allowed. You can also leave out the country code (EP) and enter the number as follows: 07109822, 07109822.2.
WO (PCT) application numbers in Espacenet consist of the country code WO followed by the year of filing (four digits), the country code of the country where the application was filed (two characters) and a five-digit serial number, adding up to a fixed length of 13 characters.
To find, for example, PCT application PCT/IB2007/51010, you have to type in WO2007IB51010. If you are searching for application number PCT/MX2007/000062, you should enter WO2007MX00062 (i.e. remove the leading zero).
Kind codes A, B or C should not be entered, as these types of document are automatically retrieved. However, in some cases you may need to enter the kind code (D-Z) immediately after the country code and serial number in order to view the patent document (e.g. KR19910000410U).
To retrieve all the documents having a particular country codein 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 datefield.