A tax invoice under GST has to carry specific things: both parties' GSTIN, the place of supply, an HSN or SAC code per line, the rate applied, and the tax shown as either CGST plus SGST or as IGST — never both. Which split applies is decided by whether the supply crosses a state boundary, and that is readable from the first two digits of each GSTIN. This generator works that out for you, prices every line, groups the tax into bands by rate, rounds the payable amount to the nearest rupee and records the adjustment, spells the total out in words, and produces a PDF you can send.
Features
CGST and SGST split within a state, IGST across states, decided from the GSTINs
GSTIN validated properly, including the check digit
Per-line HSN or SAC code, quantity, rate, discount and GST rate
Tax summary banded by rate, as the invoice format expects
Payable amount rounded to the nearest rupee with the round-off shown
Amount in words using the Indian numbering system — crore, lakh, thousand
Supplier and recipient blocks, place of supply, notes and a signature line
How to use the GST Invoice Generator
Fill in the invoice number, date and place of supply
Enter the supplier and recipient details, including both GSTINs
Add a line per item with its HSN code, quantity, rate and GST rate
Check the tax split and the total in words, then generate the PDF
Example
Input
Supplier 27AAPFU0939F1ZV, recipient 29AAPFU0939F1ZR, one line: consulting, SAC 9983, 25,000 at 18%
Output
Taxable 25,000.00 · IGST 4,500.00 · Total payable 29,500.00 — Rupees Twenty Nine Thousand Five Hundred Only
State codes 27 and 29 differ, so the supply is inter-state and IGST applies rather than CGST plus SGST.
Common errors & troubleshooting
The GSTIN is rejected as invalid. — The last character is a check digit computed from the other fourteen. A single mistyped character fails it — re-read the number from the registration certificate.
The wrong tax split is being applied. — It follows the two state codes. If one GSTIN is missing, or the supply is a special case such as an export or an SEZ sale, set the supply type manually.
The total is a rupee off what the customer expects. — The payable amount is rounded to the nearest rupee and the difference is shown as a round-off line, which is the normal convention. Compare the taxable value if the gap is larger.
A line's tax looks a paisa out. — Each line is rounded to two decimals before the CGST and SGST halves are taken, and the halves are made to add back to the line's tax. That is the standard approach.
Frequently asked questions
How is CGST and SGST versus IGST decided?
By the place of supply relative to the supplier's state. In practice the first two digits of each GSTIN carry the state code, so different codes mean IGST and matching codes mean an equal CGST and SGST split.
Is my invoice data sent anywhere?
No. The arithmetic and the PDF are both produced in this tab, so client names, GSTINs and amounts stay on your device.
Does this file the invoice with the GST portal?
No. It produces the document. Filing, e-invoicing and IRN generation are separate processes handled through the portal or your accounting software.
What is the difference between an HSN and a SAC code?
HSN codes classify goods and SAC codes classify services. The field takes either, and which one you need depends on what the line is selling.
Can I use this for a bill of supply or an export invoice?
The layout is a tax invoice. For a zero-rated export you can set the GST rate to 0 and the supply type manually, but check the wording your case requires.
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