GST Invoice FAQ: 12 Common Questions Answered

Any GST-registered business supplying taxable goods or services must issue a GST-compliant tax invoice. Unregistered suppliers (below ₹20 lakh threshold) issue regular invoices without GST.

Supplier GSTIN, invoice number (unique per financial year), invoice date, recipient's name and GSTIN (for B2B), description of goods/services, HSN/SAC code, taxable value, GST rate, CGST/SGST or IGST amount, and total invoice value.

Intra-state supply (same state): CGST + SGST split equally (e.g., 18% GST = 9% CGST + 9% SGST). Inter-state supply (different states or export): IGST at the full rate (e.g., 18% IGST).

HSN (Harmonized System of Nomenclature) is a 6–8 digit code that classifies goods for GST. SAC codes classify services. Businesses with turnover above ₹5 crore must include 6-digit HSN codes.

For goods: within 30 days of supply. For continuous supply of goods: within 30 days of agreed billing date. For services: within 30 days of supply (45 days for banking and insurance).

A bill of supply is issued instead of a tax invoice when GST is not applicable — e.g., for exempt goods/services or by a composition scheme dealer.

A document accompanying goods in transit that do not yet have an invoice — e.g., goods sent for job work, consignment, or exhibition.

Yes. You can issue a handwritten GST invoice as long as it includes all required fields. However, digital/typed invoices are standard and required for e-invoicing above ₹5 crore threshold.

E-invoicing is mandatory for businesses with AATO above ₹5 crore. Invoices must be reported to the Invoice Registration Portal (IRP) before sharing with the buyer. The IRP generates an IRN (Invoice Reference Number) and QR code.

Use Templix AI's free GST Invoice Template — includes all required fields (GSTIN, HSN/SAC, CGST/SGST/IGST), exportable to PDF and Word, no sign-up.

Must be unique for each financial year, alphanumeric, up to 16 characters, and sequential. Example: INV/2026-27/001. You cannot use the same number in two consecutive years.

Issue a credit note (to reduce the amount) or debit note (to increase the amount), referencing the original invoice. Do not cancel and reissue with the same number.