https://www.epo.org/en/searching-for-patents/helpful-resources/asian/india/numbering

Numbering system - India

Document types and kind codes

18 month publication

  • publication of application
  • pre-grant opposition
  • WIPO code: A

Publication of specification

  • post-grant opposition (>2005)
  • WIPO code: A1

Patent of addition

  • published with a new number
  • WIPO code: A7

Number formats

yyyyJTnnnnnn application numbers (> 2016) 

  • four digits for year of filing (yyyy)
  • one digit for the jurisdiction of the Indian Patent Offices (J)
  • one digit for type of application (T)
  • six digits for continuous running serial numbers for all Patent Offices in India (n)

J = jurisdictions of Indian Patent Offices:
1 = Delhi
2 = Mumbai
3 = Kolkata
4 = Chennai 

T = type of application:
1 = Ordinary Application
2 = Ordinary-Divisional Application
3 = Ordinary-Patent of Addition Application
4 = Convention Application
5 = Convention-Divisional Application
6 = Convention-Patent of Addition Application
7 = PCT National Phase Application
8 = PCT National Phase-Divisional Application
9 = PCT National Phase Patent of Addition Application 

nnnnn/LLL/yyyy    application numbers (> 1972)

  • up to five digits for the serial number (n)
  • three digits for the filing office/city code (L)
  • four digits for the year (y)

(nnnnn/LLLNP*/yyyy  PCT application numbers >2003)
(IN/PCT/yyyy/nnnnn/LLL    PCT application numbers < 2003)

* NP for national phase

Filing offices (LLL) 
Kolkata (formerly Calcutta)   = KOL (CAL) 
Mumbai (formerly Bombay)  = MUM (BOM)  
Chennai (formerly Madras)   = CHE (MAS)  
Delhi   = DEL  

nnnnnn    publication numbers for granted patents (> 1912)

  • up to six digits for the serial number (n)
  • no city code
  • no year

Publication of an application is not assigned a separate publication number and is published with the application number.