GSTIN
GSTIN (Goods and Services Tax Identification Number) is the unique 15-digit registration number assigned to every business registered under India’s GST law.
GSTIN is a 15-character alphanumeric code assigned to every taxpayer registered under GST. It encodes the state code, PAN of the business, and a few check digits, making it possible to identify the registered business and its home state directly from the number.
A GSTIN is required if your annual turnover crosses the GST registration threshold (which varies by state and by whether you supply goods or services), or if you voluntarily register to claim input tax credit or invoice larger clients who require it.
Your GSTIN should appear on every GST-compliant invoice you issue, along with your client’s GSTIN if they’re also GST-registered.