Examples of Application Number Formatting by Country

The format in which patent application numbers can be written vary hugely in different nations and under different regional authorities.  The table below is organised to give formatting information on the top filing countries which have nuances in their application number appearance differing from the standard

A little more explanation on the Japanese, American and European systems is given below the table.  The aim is to give you a straightforward and easily referable table to quickly interpret patent application numbers.  Use on its own or alongside Examples of Publication Number Formatting by Country.

The original format as recognised in each country is given, followed by the “EPODOC” recognised format (useful for searching application number through various patent search databases).  An explanation of how the original format of the application number is built up is given in the final column.  This column really helps to decipher the (sometimes obscure) historical reasons for patent offices originally adopting such a format.

Country or Organisation Example of Application NumberCorrected Presentation adhering to Standard Format (EPODOC)Explanation
Australia (AU)59195/69


AU 20020254345

Old number format. Sequential numbering series.

Number format from July 2002. First 4 digits are the year of filing, the 5th digit denotes the application type (2-7 for patents), and the last 5 digits are the serial number.
Canada (CA)183048

CA19730183048 (leading zero to make up 7 digits)

CA20042525122 (full 4-digit year)
Before 1989, a similar sequential numbering system was used, starting from 1 and ending at 999,999.

Numbering system for patent applications filed on or after October 1, 1989. The starting number is 20000001 and consecutively follow a series.
China (CN)95 1 08192.6 or 95108192.6

CN19951008192 (full 4-digit year; add in leading zero to give 6-digit serial number)

CN20058045036 (remove 1st leading zero to give 6-digit serial number)
Format between 1st April 1985 to 30th September 2003. The first two digits indicate the last two numbers of the filing year. The third digit denotes the type of application (1 for patent application). The next five digits are the serial number.

New numbering system from October 1, 2003. The first four digits indicate the year. The fifth digit denotes the type of patent application. The next seven digits indicate the serial number.
European Patent (EP)04732551.9EP20040732551Numbering format up to 1st January 2002. The first 2 digits indicate the last two numbers of the filing year. The next 2 digits denote the place of filing, and the remaining digits indicate the serial number given by the Receiving Office. A check digit can be added to the end.

On or after 1 January 2002.
The application number consists of 9 digits. The first 2 digits indicate the filing year. The last digit
is a check digit. The remaining 6 digits in between are used for
consecutively numbering the applications in the order in which they are filed.
France (FR)96 03098FR19960003098A 2 digit year followed by a 5-digit serial number in sequential order according to year.
Germany (DE)195 00 002.1

DE19951000002 (full 4-digit year; digit representing application type moved to position proceeding the year; leading zeros added to give 6-digit serial number).

Numbering format up to 2003. The first digit indicates the type of application (1 for patent). The next 2 digits are the filing year. the remaining digits are the serial number.

Numbering format (as of 1st January 2004). First two digits indicates application type (10 for patent). The 4-digit year of filing is next, followed by a 6-digit serial number, and an optional check digit.
Japan (JP)58-186061



Numbering format up to January 2000. The first 2 digits indicates the Japanese Imperial Year (see below) and the next 6 digits are the application number.

Number format from 1st January 2000.First 4 digits represent the Gregorian calendar year, and next 7 digits represent the serial number.
Patent Cooperation Treaty (PCT)PCT/GB02/02806WO2002GB02806 (WO replaces PCT/GB to indicate a PCT application)The two digits proceeding the first "/" are the country code of the Receiving Office. The next 2 digits represent the filing year, whilst the last 5-digits are the serial number.
United Kingdom (GB)

GB19700041352 (full 4-digit year at start; add leading zeros to give 7-digit serial number)

GB19930022552 (full 4-digit year at start; add leading zeros to give 7-digit serial number)
Format of 1949 GB Patent Act; Application number given by an annual series, and the two digits proceeding the "/" represent the year of application.

Format of 1977 GB Patent Act; Serial number given by an annual series, first two digits represent the year, and the number proceeding the "." is the check digit.
United States of America (US)11/409,718US20060409718The 2 digits preceding the "/" are the series code, based on the date the application was filed (see below).

Japanese Numbering System

The Japanese patent numbering system uses the 2-digit Imperial Year which is based on the Year of the Emperor reign.

Between 1926-1989 Hirohito, the 124th Emperor of Japan, reigned.  Upon his death, the name of the era (Showa) was also made the Emperor’s own name.  In terms of patents, the letter “S” may appear at the start of an application or publication number to denote its filing date was within the Showa Era.  To calculate the Gregorian calendar year from the Imperial Year throughout the Showa era, use the simple equation below.  The final year in the Showa era is 64, and is accurate up to the date of Hirohito’s death (7 January).

1926 – 1989 : Hirohito Reign (Showa Year)             Imperial Year = Gregorian Year – 25 (64 or less)

Since 1989 to present day, Akihito has reigned.  The era is known as the Heisei and is calculated as below.  The year 1989 can be referred to as 64 (for the Showa Year) or as 1, from the 8th January, for the Heisei Year.  a patent application number may have the letter “H” at the start to denote the Heisei era.

1989 – 2000 : Akihito Reign (Heisei Year)                Imperial Year = Gregorian Year – 88 (1-11)

An unexamined JP patent application is published 18 months after its earliest priority date (ie. Laid open) and has a kind code suffix “A”.  An unusual feature is that patents are not automatically examined.  An examined JP patent is published pre-grant and has a similar number to the laid-open publication number but with a kind code suffix “B”.

United States of America Numbering System

The United States use a series code to denote the range of years in which the application was filed.  For years prior to 1915, no series code exist.  For a US application to be uniquely identified, the filing date of the application must be provided in addition to the series code and serial number.  A table equating the series code with the year is shown below.

Series NumberFiling Year Range
21935 - 1947
31948 - 1959
41960 -1969
51970 - 1978
61979 - 1986
71987 - 1992
81993 - 1997
91998 - 2001
102002 -2004
112005 - present

 European Numbering System

The application number for an EP patent contains third and fourth digits which indicate the country of processing of the application.  The table below shows a selection of codes for certain Receiving Offices, found in the Official Journal of the EPO (OJ 10/2001 p.465).

Designated Country/RegionSeries Code
EPO Munich0
EPO The Hague07
EPO Berlin09
United Kingdom (GB)25
Euro-PCT Route27