README.md

GSTIN regex and its checksum

GSTIN regex

\d{2}[A-Z]{5}\d{4}[A-Z]{1}[A-Z\d]{1}[Z]{1}[A-Z\d]{1}

Format details

• First 2 digits of the GST Number will represent State Code as per the Census (2011).
• Next 10 digits will be same as in the PAN number of the taxpayer.
• First five will be alphabets
• Next four will be numbers
• Last will be check code
• The 13th digit will be the number of registration you take within a state i.e. after 9, A to Z is considered as 10 to 35 .
• 14th digit will be Z by default.
• Last would be the check code.

How to decode the GST CheckSum

• Javascript checksum verification
• Python Checksum verification
• Swift Checksum verification