GST Invoice Checker

Tick what your invoice already shows and this tells you what is missing. Not another invoice generator — those exist. This is the check nobody does until a buyer’s accountant does it for them.

What usually goes missing

In the invoices we see while building billing into stores, the same four gaps come round: no HSN or SAC code per line, no place of supply, CGST and SGST collapsed into one GST line, and an invoice series with holes in it.

None of them stops you sending the invoice. All of them cause trouble later — the first three when your buyer tries to claim input credit, the fourth when somebody asks why invoice 41 does not exist.

Same state or different state is the whole thing

Within your state it is CGST plus SGST, shown as two separate amounts. Across state lines it is IGST as a single amount, and showing both is wrong. Exports are zero rated, and the invoice has to say whether you are supplying under LUT without payment of tax or with IGST paid and a refund claimed.

This is the part software gets wrong when it was configured once and never checked against a real interstate sale. Setting it up properly in WooCommerce is covered in WooCommerce GST setup, and capturing a buyer GSTIN at checkout is the piece most stores skip.

The buyer GSTIN

On a B2B invoice it is not optional. Without it your customer cannot claim input credit, which is usually the entire reason they asked for a GST invoice rather than a receipt. If you sell to businesses and your checkout has no GSTIN field, that is the first thing to fix.

What this is not

A checklist against the usual rules, not tax advice. It does not cover reverse charge in detail, e-invoicing thresholds, composition scheme, or your particular situation. Your accountant decides; a web page does not.