When is GST charged as CGST plus SGST versus IGST?

It depends on the place of supply. If the supplier and recipient are in the same state, the tax splits equally into CGST and SGST. If they are in different states, the full amount is charged as IGST. The builder reads the two state fields and applies the correct split automatically.

What is a GSTIN and where does it go?

A GSTIN is the 15-character Goods and Services Tax Identification Number assigned to every registered business. Both the supplier's and the recipient's GSTIN must appear on a B2B tax invoice. The builder includes fields for both.

What are HSN and SAC codes?

HSN (Harmonised System of Nomenclature) codes classify goods and SAC (Services Accounting Code) codes classify services. They are mandatory on GST invoices above the prescribed turnover thresholds. Enter the correct code per line item.

How are the GST rates applied?

Tax on each line is its taxable value multiplied by the chosen GST slab. For an intra-state supply at 18%, that 18% is split into 9% CGST and 9% SGST. For an inter-state supply the full 18% is IGST. The builder sums each component across all lines.

What is the reverse-charge mechanism?

Under reverse charge the recipient, not the supplier, is liable to pay the GST to the government. The invoice must clearly indicate when reverse charge applies, so the builder includes a reverse-charge flag that prints on the invoice.

Indian GST Invoice Builder

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A GST-compliant tax invoice without the tax-table guesswork

Indian GST invoicing has strict requirements: both parties’ GSTINs, HSN or SAC codes per line, the correct CGST/SGST or IGST split, and a reverse-charge indicator. This builder collects each field, decides the tax treatment from the place of supply, and produces a clean tax invoice you can file or paste into accounting software.

How it works

The core rule is the place-of-supply test. The builder compares the supplier’s state with the recipient’s state: when they match, the supply is intra-state and each line’s GST is split equally into CGST and SGST; when they differ, the supply is inter-state and the full GST is charged as IGST. Each line’s taxable value is quantity multiplied by rate, and tax is that value multiplied by the chosen GST slab — 0, 5, 12, 18, or 28 percent. The builder then totals the taxable value and each tax head separately and adds them for the grand total. A reverse-charge flag is printed when set, signalling that the recipient bears the GST liability.

Tips and example

Always confirm the recipient’s state from their GSTIN — the first two digits are the state code, and getting it wrong flips your invoice between CGST/SGST and IGST. A ₹50,000 intra-state supply at 18 percent produces ₹4,500 CGST and ₹4,500 SGST for ₹9,000 total tax; the same supply inter-state produces a single ₹9,000 IGST line. Use the correct HSN/SAC code per item, since GST rates are tied to classification. For exports and reverse-charge supplies, set the relevant flag so the invoice states the treatment clearly.