https://www.epo.org/en/node/numbering

Numbering system - Japan

Document types and kind codes

KOKAI (A, U) 公開
  • unexamined patent publication (A)
  • unexamined utility model publication (U)
KOKOKU (B, Y) 公告
  • examined patent publication (old law) (B)
  • examined utility model publication (old law) (Y)
TOROKU (B, U) 登録
  • granted patent publication (new law) (B)
  • granted utility model publication (new law) (U)
KOHYO (A, T) 再発表  
  • PCT application entering national phase in Japan (A, T)
SAIKOHYO (A) 発表
  • Japanese PCT application entering national phase in Japan (A)

Number formats

yy-nnnnnn 
  • two digits for the year (y)
  • up to six digits for the number (n)
  • application number, unexamined publication number, examined publication number (old law)
  • from 2000 onwards: four-digit Western year (yyyy-nnnnnn)
nnnnnnn
  • seven digit number (n), no year
  • grant numbers

Japanese number formats (Patents)

 

OLD LAW:
 
  • application
    yy-123456
  • unexamined publication
    yy-123456
  • examined publication
    yy-123456
  • registration (no publication)
    no. > 1 000 000
NEW LAW (1996):
 
  • application
    yy-123456
  • unexamined publication
    yy-123456
  • granted patent (publication)
    no. > 2 500 000
first publication: 29 May 1996
document no.: 2 500 001


NOTE:
from 2000 onwards the four-digit Western year is used instead of the Japanese imperial year

Japanese number formats (Utility Models) 

OLD LAW:
 
  • application
    yy-123456
  • unexamined publication
    yy-123456
  • examined publication
    yy-123456
  • registration (no publication)
    1~approx 2 000 000

NEW LAW (1994):
 
  • application
    yy-123456
  • granted utility model publication (without examination)
    no. > 3 000 000
first publication: 26 July 1994
document no. 3 000 001

 

Japanese imperial years vs. Western years

SHOWA (SHO, S) 昭和
  • reign of Emperor Hirohito
  • 1926 to 1989
HEISEI (HEI, H) 平成
  • reign of Emperor Akihito
  • 1989 to date
REIWA (REI, R) 令和
  • reign of Emperor Naruhito
  • 1 May 2019 to date

SHOWA + 25 = Western year
HEISEI + 1988 = Western year
REIWA + 2018 = Western year

NOTE:

1) The last year SHOWA is the first year HEISEI (SHOWA 64 = HEISEI 01 = 1989).
2) The western year 2019 is until 30 April HEISEI 31, and starting from 1 May REIWA 1