Postal Index Number or more popularly known as PIN code that we usually see at the end of any complete address of India refers to a six-digit numeric code in the Indian postal system by India post.
The PIN code was first introduced on 15th August, 1972 by Shriram Bhikaji who was the then Additional Secretary in the Ministry of Communications.
A new system was felt required to simply the process of manual sorting and delivery of mails. Presence of different languages, places with similar names created a lot of confusion and a standard procedure was needed to simplify the process.
Hence, PIN codes were introduced which identified cities, districts, and states with unique codes which helped in eliminating confusion.
PIN code structure
There are nine postal zones in India, including eight geographical region zones and one for the Indian Army. The first digit of a PIN code indicates the zone, second digit the sub zone, the third digit indicates the sorting district within that region and the last three digits indicate the specified post office within that district.
Post office zones
Northern zone - 1,2
Western zone - 3,4
Southern zone - 5,6
Eastern zone - 7,8
Army postal zone – 9
State-wise
1. Delhi, Haryana, Punjab, Himachal Pradesh, Jammu and Kashmir, Ladakh, Chandigarh
2. Uttar Pradesh, Uttarakhand
3. Rajasthan, Gujarat, Daman and Diu, Dadra and Nagar Haveli
4. Maharashtra, Goa, Madhya Pradesh, Chhattisgarh
5. Telangana, Andhra Pradesh, Karnataka
6. Tamil Nadu, Kerala, Puducherry, Lakshadweep
7. West Bengal, Odisha, Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura, Meghalaya, Andaman and Nicobar Islands, Assam, Sikkim
8. Bihar, Jharkhand
9. Army Post Office (APO), Field Post Office (FPO)
How the system works
Each PIN is mapped to one delivery post office which receives all the mails to be delivered to different offices under its jurisdiction. The delivery post office can be the General Post Office, a head office, or a sub-office which is usually located in urban areas. From these offices, the mails are sorted and sent to the relevant sub-offices which finally deliver the mail to us with the help of a postman.
