PIN Code
Postal Index Number — India's 6-digit postal code system introduced in 1972 to identify post offices across the country.
The PIN (Postal Index Number) code system was introduced on August 15, 1972, by India Post to simplify mail sorting across a vast and linguistically diverse nation. India's PIN codes are 6 digits long, with the first digit representing one of nine postal zones (1 for Delhi and surrounding areas, 5 for Karnataka and Andhra Pradesh, etc.). The second and third digits together identify a sorting district, and the last three digits specify an individual post office.
As of 2024, India has over 155,000 post offices — the largest postal network in the world — each with its own PIN code. The system was designed so that mail could be routed by machines and clerks who might not read the local script.
PIN codes play a growing role in Indian e-commerce, banking (KYC verification), and government welfare distribution, where they help validate addresses and determine service availability.