GSTIN (GST Identification Number)

GSTIN stands for Goods and Services Tax Identification Number. It's a 15-character alphanumeric code assigned to every business or individual registered under GST in India. The format: first 2 digits are the state code, next 10 digits are the PAN number, the 13th digit is the entity number (for multiple registrations in the same state), the 14th is "Z" by default, and the 15th is a check digit.

You need a GSTIN if your annual aggregate turnover exceeds ₹20 lakh (₹10 lakh in special category states like Manipur or Mizoram). Even below the threshold, voluntary registration is common — many corporate clients won't work with unregistered vendors, and registration lets you claim input tax credit on business expenses.

To register, apply on the GST portal (gst.gov.in) with your PAN, Aadhaar, bank account details, and proof of business address. The process is fully online and typically takes 3-7 working days. Once approved, your GSTIN is active and must appear on every tax invoice you issue.

Your GSTIN must be displayed on your invoices, your website, and your business signage. When billing a GST-registered client, you need their GSTIN on your invoice as well — without it, they can't claim ITC. Always verify client GSTINs on the GST portal before invoicing to avoid mismatches that trigger notices.

PropCraft's GST invoicing feature validates GSTINs, auto-determines IGST vs CGST+SGST based on state codes, and includes all mandatory fields on every invoice.