Present multiple GST rates on one invoice by keeping each independently treated supply's classification, taxable value, rate and tax amount clear. Add a rate-wise summary that reconciles to the line details and invoice total. First confirm that the commercial arrangement permits separate treatment. Composite or mixed supplies require their own analysis; putting components on different rows does not automatically make them independent supplies.
Verify the nature and rate of each item
Use approved HSN or SAC records and current rate references for the transaction date. Do not inherit the first line's rate for the whole bill. Similar product names or a shared brand do not prove identical classification or conditions.
Identify exempt and zero-rated lines distinctly where relevant. A generic zero percentage can conceal an exemption, a qualifying export route or an incomplete master entry. Keep the reason in the records and use a customer-readable description. The tax summary should explain the invoice's actual treatment, not merely list the percentages stored in the system.
Illustrative two-rate invoice
Assume independently treated category A has taxable value ₹15,000 at a confirmed illustrative aggregate rate of 5%, and category B has ₹12,000 at 18%. Tax on A is ₹750 and tax on B ₹2,160. Total taxable value is ₹27,000, total GST ₹2,910 and invoice total ₹29,910.
| Rate group | Taxable value | Aggregate GST | Gross amount |
|---|---|---|---|
| Assumed 5% | ₹15,000 | ₹750 | ₹15,750 |
| Assumed 18% | ₹12,000 | ₹2,160 | ₹14,160 |
| Total | ₹27,000 | ₹2,910 | ₹29,910 |
For an ordinary intra-State supply in a State, the corresponding totals are CGST ₹1,455 and SGST ₹1,455, using the relevant component rates within each group. For an ordinary inter-State supply, the assumed IGST total is ₹2,910. Confirm the nature-of-supply decision separately.
Allocate an overall discount correctly
Read the offer terms to determine which items receive the discount. Where a proportionate allocation fits an overall ₹2,700 discount on the example's ₹27,000 basket, category A receives ₹1,500 and category B ₹1,200. Their revised taxable values are ₹13,500 and ₹10,800.
At the same assumed rates, tax becomes ₹675 plus ₹1,944, totalling ₹2,619. Gross payable becomes ₹26,919. Do not subtract ₹2,700 only from the original grand total while leaving the tax bases unchanged if the reviewed discount qualifies to reduce taxable value. Conversely, do not treat an advance or withholding as an invoice discount.
Review common charges before allocation
Freight, packing or other supplier charges may form part of taxable value depending on the arrangement. Determine whether they belong to one supply, several independent lines or another separately analysed service. Then use a supportable allocation where necessary.
Direct attribution is often useful where evidence exists. If one item requires a special crate and another uses ordinary packaging, the actual charges may be more informative than an equal split. Preserve the method and contract terms. Do not allocate all common charges to the lowest-rate group to produce a preferred tax result.
Make line details and summaries agree
The invoice should show descriptions, quantities and units for goods, appropriate codes, net values and rates clearly. A footer containing only one rate can mislead customers where the bill has several. Use a rate-wise tax summary that adds to the same totals shown in the ledger.
Check the meaning of each percentage label. An aggregate 18% heading and individual 9% CGST and 9% SGST columns should not appear as three separate charges. Use column names that let customers understand the components without reconstructing the calculation from a total-tax number.
Preserve inclusive-price assumptions
If some lines have inclusive prices and others exclusive prices, identify that in the order and calculation working. Extract the base separately using each applicable rate for inclusive lines. A single reverse-calculation using an average rate cannot reliably divide a multi-rate total without a supported allocation.
For example, ₹1,050 inclusive at an assumed 5% yields ₹1,000 base and ₹50 tax, while ₹1,180 inclusive at 18% yields ₹1,000 base and ₹180 tax. Both bases are equal even though their gross prices differ. Keep the line-price basis clear before applying a basket discount.
Handle returns by original line treatment
A partial return should identify the actual item, original taxable value, tax rate and prior adjustments. Do not reverse a proportion of total invoice tax merely because the return represents a proportion of total invoice value. Different rates make that shortcut unreliable.
If category B worth ₹2,000 is returned under a supported adjustment at the assumed 18% rate, the illustrative tax reduction is ₹360. It is not calculated using the example invoice's blended tax percentage. Preserve original references in the credit-note working.
Test the full output
Recalculate one mixed-rate example independently and compare the PDF, ledger, rate summary and applicable structured reporting data. Include discounts and common charges in the test, because simple two-line examples may not reveal allocation defects.
A clear multi-rate invoice keeps the supply analysis, taxable bases and tax components connected. Once independent treatment is confirmed, transparent line values and rate summaries let the customer and accounts team reconcile the same document without relying on an unexplained blended rate.