A return does not want your invoices — it wants them grouped, and grouped in a particular way. Registered buyers are listed individually. Consumer sales are aggregated by state and rate, except for large inter-state invoices, which are itemised separately. Then everything has to reconcile rate by rate against your books. Paste the invoice rows as CSV and all four tables are built, with the tax split correctly at each row: an intra-state supply into equal CGST and SGST halves, an inter-state one into IGST at the full rate. The checks catch what a portal rejects at upload rather than at assessment.
Features
B2B, B2CL, B2CS and rate-wise tables built from one list of rows
Tax split per row — CGST and SGST intra-state, IGST inter-state
GSTIN check digit verified, so a mistyped number is caught before filing
Duplicate invoice numbers within the period are flagged
Rates outside the published set and malformed state codes rejected
Place of supply cross-checked against the buyer state
Rate-wise and B2B tables export as CSV
How to use the GST Filing Prep
Download the template, or paste your rows straight in
Fix anything the checks flag
Read the four tables and reconcile the totals against your books
B2CS · place of supply 29 · 5% · taxable 1200.00 · IGST 60.00
A small inter-state consumer sale aggregates rather than being itemised.
Common errors & troubleshooting
A GSTIN was rejected. — Its check digit does not match the rest of the number, so it is mistyped. The portal applies the same test and would refuse the row.
A rate was rejected. — Only the rates in actual use are accepted. A rate of 17% or 20% is almost always a typing slip for 18%.
The place of supply contradicts the intra-state flag. — The buyer GSTIN starts with a different state code from the place of supply, but the row is marked intra-state. One of the two is wrong.
An invoice number repeats. — Each invoice number must be unique within the period. Two lines of the same invoice are fine — give them the same number and different rates.
Frequently asked questions
Does this file the return for me?
No. It prepares and checks the summaries so the figures are right and the data would be accepted. Filing happens on the portal, with your own credentials.
One invoice has two tax rates. How do I enter it?
As two rows with the same invoice number and different rates. The invoice count treats them as one invoice; the rate-wise table splits them correctly.
What decides B2CL rather than B2CS?
An unregistered buyer, an inter-state supply, and a taxable value above the itemisation threshold. Anything else from an unregistered buyer aggregates into B2CS by state and rate.
Why is the customer GSTIN blank on some rows?
Because the buyer is not registered — that is what makes the sale B2C. Leave it empty rather than putting a placeholder in.
Can I paste an export from my accounting software?
If it has the right column names, yes. Download the template to see them; the reader is tolerant about spacing, case and currency symbols in the numbers.