DIGIPIN - Digital Address of your location

(National Addressing Grid)

Waiting for GPS
The India Post is spearheading an initiative to implement a standardized, geo-coded addressing system across India. This effort aims to simplify address solutions for efficient delivery of public and private services. In collaboration with IIT Hyderabad, the India Post has developed the Digital Postal Index Number (DIGIPIN), a national-level addressing grid-based system. DIGIPIN is poised to serve as a robust foundation for Geospatial Governance, promising improvements in public service delivery, quicker emergency responses, and enhanced logistics efficiency.

The introduction of DIGIPIN marks a transformative leap in India's digital journey, bridging the gap between physical locations and their digital counterparts.

PINCODE was introduced in India on 15th August, 1972 to identify the loction by codifying the location in 6 digit PINCODE. As it is well known that the same PINCODE is used for main Post Office and Branch Post Offices linked to it, resultantly the PINCODE serves for larger geographical area.

In modern world where geolocation is specific because of advanced GPS devices, India Post in collaboration with IIT Hyderabad has come up with an idea to integrate th GPS location of a service user by codifying the geo- cordinates known as latitute and longitute to serve the customer in a better way. The beta version of DIGIPIN has been released by INDIAPOST for comments, suggestions etc to refine the concept and build final version of it.

What is DIGIPIN?

The Department of Posts also know as India Post is undertaking a project to establish a standardized, nationwide geo-coded addressing system by developing a National level Grid known as DIGIPIN.
The implementation of this Digital Addressing system would ensure simplified addressing solutions for citizen centric delivery of public and private services. A standardized geo-coded addressing system would enhance India’s geo-spatial structure. It would add to the geospatial knowledge stack of the country in line with the National Geospatial Policy 2022, which seeks to strengthen the geospatial sector to support national development, economic prosperity and a thriving information economy.
This document contains the technical details of the DIGIPIN, the National Level Addressing Grid

Design Approach

What is the Core Concept behind DIGIPIN?

Department of Posts have collaborated with IIT Hyderabad for developing a grid based addressing system which has been designated DIGIPIN. DIGIPIN is visualised as an alpha numeric offline grid system that divides the geographical territory of India into uniform 4- meter by 4-meter(approx.) units. Each of these 4m X 4m units (approx.) is assigned a unique 10-digit alphanumeric code, derived from the latitude and longitude coordinates of the unit.

This alphanumeric code serves as the offline addressing reference for any specific location within the DIGIPIN system. DIGIPIN is thus strictly a function of the latitude and longitude of the location represented as a grid value. The system is designed to be scalable, adaptable, and integrated with existing GIS applications.

DIGIPIN layer

DIGIPIN layer will act as the addressing reference system which will be available offline and can be used for locating addresses in a logical manner with directional properties built into it due to the logical naming pattern followed in its construction. DIGIPIN can be also used for emergency rescue operations, national disasters like flood. DIGIPIN is proposed to be fully available in public domain and can be easily accessed by everyone. Since no private address data is stored against DIGIPIN grid value, there is no privacy concern associated with DIGIPIN being in public domain. DIGIPIN Grid system being an addressing referencing system, can be used as the base stack for development of other ecosystems where addressing is one of the processes in the workflow.

How will DIGIPIN work? 

DIGIPIN : Code Architecture

The Detailed structure is such that the DIGIPIN is essentially an encoding of the latitude and longitude of the address into a sequence of alphanumeric symbols using the following 16 symbols: 2, 3, 4, 5, 6, 7, 8, 9, G, J, K, L, M, P, W, X.

The process of identifying the cells is done in a hierarchical fashion. The encoding is performed at various levels, and the basic idea is the following:

  • A bounding box is used that covers the entire country.
  • The bounding box is split into 16 (i.e., 4x4) regions. Each region is labeled by one of symbols 2, 3, 4, 5, 6, 7, 8, 9, G, J, K, L, M, P, W, X. The first character in the code would identify one of these regions. This is called the level-1 partition.
  •  Each region is then subdivided into 16 subregions in a similar fashion. Each of the 16 subregions are labeled by the 16 characters. For a given region, the subregion is identified by the second character of the code. Therefore, the first two characters of the code uniquely identify one of the 16^2=256 subregions. This is called the level-2 partition.
  • The encoding of successive characters, and therefore the next 8 levels is done in an identical fashion. The 10-symbol code therefore uniquely identifies one of the 16x10 cells within the bounding box.

Bounding box:

Following are the details of the bounding box used:
  • Longitude 63.5 – 99.5 degrees eas
  • Latitude 2.5 – 38.5 degrees north
  • The Coordinate Reference System (CRS) used in the proposed code design is EPSG:4326. Using EPSG:4326 (also known as WGS84) has several advantages like wide recognition and adoption, simplicity and global coverage
DIGIPIN - Digital Address of your location

The choice of the corner points of the bounding box are based on the following considerations:

  • This includes the entire territory of India.
  • Includes the maritime Exclusive Economic Zone (EEZ), and therefore DIGIPIN allows to provide addresses to Indian assets in the sea (oil rigs, future man-made islands, etc.), or even potentially be used to locate regions in the sea by the maritime sector. The maritime EEZ is computed assuming 200 nautical miles extent from the coastline.
  • The Indian mainland is covered by only 8 regions, and therefore can be labeled with the digits 2-9 at level-1.
  • Level-1 grid lines do not cut through cities with very large population
  • The level-10 cells would be almost rectangular, but the dimensions would vary based on the latitude. This would translate to a cell of size smaller than 3.8m x 4m if measured at the equator, and this is reasonable given the accuracy of most current commercially available Global Navigation Satellite System (GNSS)

Properties of DIGIPIN

  • DIGIPIN contains the geographic location of the area. It is possible to extract the latitude and longitude of the address from the DIGIPIN with low complexity.
  • DIGIPIN has been designed for the Indian context. All points of interest to India (including maritime regions) can be assigned codes, and it is possible to assign unique digital addresses even in areas that are very densely populated.
  • The format of the DIGIPIN is intuitive and human-readable. Effort was made to infuse a sense of directionality within the format of DIGIPIN.
  • DIGIPIN is independent of the land use pattern and the structure built. Note that DIGIPIN is designed as a permanent digital infrastructure, that does not change with changes in the names of state, city or locality, or with changes in the road network in an area. The DIGIPIN is designed to be robust to accommodate future developments and changes. The arrival of a new building in a community, or even a new village or city in a district, or changes in the name of a road or locality will not affect the underlying DIGIPIN.
  • The length of the DIGIPIN is designed to be as small as possible in order to provide an efficient digital representation of addresses.

Labelling of regions at various levels

Level 1:

  • Level-1 labelling ensures that the mainlandis labelled using only the digits 2-9.
  • Codewords starting with P, W and X are reserved for future or special uses
DIGIPIN - Digital Address of your location
DIGIPIN - Digital Address of your location

Level 2:

  • Each Level-1 region is further split into 16 sub-regions called Level-2 regions as illustrated in the figure below. The regions are hierarchically partitioned into sub- regions in an identical fashion.
  • For Levels 2 to 10 the same labeled grid is used, with the labeling performed in a hierarchical fashion. 
  • Symbols are assigned in anticlockwise fashion, spiraling outwards. Note that this labeling grid is different from the grid used for level-1. The grid used for levels 2-10 provide some sense of directionality and adjacency: cells labeled by consecutive symbols (such as 6 and 7) are geographical neighbors. 
DIGIPIN - Digital Address of your location
The level-1 grid, on the other hand, is designed to use numerals 2-9 for mainland India. Further, using two different grids at level-1 and levels 2-9 avoids inadvertent labelling of locations outside India using the symbols P, W and X at level-1.

Code Architecture explanation through illustration:

the geographical coordinates of Dak Bhawan (28.622788°N, 77.213033°E) are marked with a red star on the India base map. The figure demonstrates the selection of DIGIPIN symbols at each level, based on the grid encompassing Dak Bhawan. The DIGIPIN of Dak Bhawan is 39J 49L L8T4:
Level - 1
Level - 2
Level - 3
Level - 4
Level - 5
Level - 6
Level - 7
Level - 8
Level - 9
Level - 10
To gather public feedback, the Department is releasing a beta version of the National Level Addressing Grid 'DIGIPIN'. Industry leaders, technical institutes, state and local governments, as well as the general public, are invited to participate and provide valuable insights. This feedback will help refine the specifications of DIGIPIN.
For further details:
- Download the technical document detailing the code and architecture of DIGIPIN grid: [Technical Document PDF Icon (2122 KB)].
- Access the beta version of the web application to capture DIGIPIN values: [digipin.cept.gov.in](http://digipin.cept.gov.in).
- Obtain the programming code of the DIGIPIN grid logic: [Click here to download TEXT Icon (3 KB)].
- Submit comments and suggestions via email to: [digipin@indiapost.gov.in](mailto:digipin@indiapost.gov.in) by 22.09.2024.
Your participation will contribute to shaping DIGIPIN into a highly effective tool for streamlined addressing and enhanced service delivery nationwide.

© DIGIPIN