HSN/SAC validation

Every item or invoice line carries an HSN code (for goods) or a SAC code (for services). Villva validates that code against the GST master, checking both its format and its existence: so an invalid code cannot reach an invoice or an e-invoice (IRN).

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Add a short screen recording here: an invoice line with the HSN/SAC field filled in, the GST rate auto-filled beside it, and the tax breakdown updating below.

How validation works

1. Enter an HSN code on a goods line, or a SAC code on a service line (on the item master or directly on the invoice line).
2. The code is checked against the GST master:
   • A valid, known code is accepted.
   • An unknown or malformed code is rejected with a clear, specific message such as “invalid HSN”, and it blocks you from confirming the invoice or generating the IRN.
3. Goods require an HSN; services require a SAC. Villva enforces the correct code type from the item type, so you cannot put a SAC on a goods line or an HSN on a service line.

Automatic rate mapping

When you enter a valid HSN, Villva suggests and auto-fills its default GST rate from the rate master, so the correct rate is applied consistently without you looking it up.

For example, entering HSN 84818090 (held at 18% in the master) validates the code and auto-fills a GST rate of 18%. Entering 99999999, which is not in the master, is rejected and blocks the invoice.

Length rules

HSN length requirements: the minimum number of digits you must quote, based on your turnover slab, are enforced according to the rule configured for your organisation. An HSN with too few digits for your slab is rejected until you supply a longer, valid code.

Where codes are maintained

HSN and SAC codes, along with bulk import and any custom codes, are maintained in the HSN/SAC code master, and the rate suggested on each line comes from the GST rate held there.