A Postal Index Number or PIN or Pincode is the post office numbering or post code system used by India Post, the Indian postal administration. PIN stands for Postal Index Number and the code is 6 digits long. The PIN was introduced on August 15, 1972.
There are nine PIN zones in India, including eight regional zones and one functional zone. The first digit of the PIN code indicates the region in which a given post office falls in. The second digit indicates the sub-region, and the third digit indicates the sorting district within the region. The final three digits are assigned to individual post offices.
The nine PIN zones cover the Indian states and union territories as follows:
1 - Delhi, Haryana, Punjab, Himachal Pradesh, Jammu & Kashmir(including Pakistan-administered Kashmir), Chandigarh
2 - Uttar Pradesh, Uttarakhand
3 - Rajasthan, Gujarat, Daman and Diu, Dadra & Nagar Haveli
4 - Goa, Maharashtra, Madhya Pradesh, Chattisgarh
5 - Andhra Pradesh, Karnataka
6 - Tamil Nadu, Kerala, Pondicherry, Lakshadweep
7 - Orissa, West Bengal, Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura, Meghalaya, Andaman & Nicobar Islands
8 - Bihar, Jharkhand
9 - Army Post office(APO) and Field Post office(FPO)