Marketplaces
Where an adapter has been checked against a real seller’s export, it says so. Where it was written from a published column layout, it says that too, and keeps saying it until you have run one of your own files through it. A tax tool that hides how confident it is is not being helpful.
Both halves of Amazon's Merchant Tax Report, read the way GST law reads them: shipments are invoices, refunds are credit notes against the original invoice, and a promotion reduces the tax as well as the base.
MTR B2C report · MTR B2B report · GST ready-to-file workbook
Meesho splits a month across two downloads. The amounts are in one and the document numbers in the other, joined on the sub-order number.
TCS sales · TCS sales return · Tax invoice details
Sales, returns, cancellations and replacements read from one file, with the event type deciding which is which.
GST sales report · GSTR return report
Forward and reverse movements arrive in one register, with the credit note number sitting on the return rows themselves.
GST sales register
Point the fields at the columns once and any spreadsheet becomes a supported source. The mapping is saved and reused every month.
Any CSV or Excel export
Not listed
Whatever you upload, fynxIQ first tells you what every sheet in it turned out to be, one word each: orders, a finished return, a cover page, or unknown. That alone is usually the answer, because most files that “do not work” are a settlement statement or a payout report rather than a sales report.
For anything it genuinely cannot place, press the button and it reads the file: what each column holds, which rows are sales and which are returns, and which state the tax belongs to. Where it cannot settle something on its own — two columns that could both be the taxable value, a state column that might be the buyer’s or the warehouse’s — it asks you, with buttons, in whichever of fourteen Indian languages you picked. Not a form. A question about the thing.
Only the column headings and a few sample values leave your browser, with anything that could name a person removed at the moment it was read. What comes back is a set of pointers from a field name to a column heading and nothing else: no figure, no tax, no decision about whether the return may be filed. All of that runs afterwards in exactly the same code that reads Amazon, and any of it can still refuse the result.
You can also point the columns yourself, and on a paid plan either route is saved and reused every month. This is the escape hatch when a built-in adapter goes stale because a marketplace renamed a column: the mapping is data rather than code, so it can be fixed in the app in a minute instead of waiting for a release.
One honest limit: a mapping cannot check itself. The arithmetic rules still run in full, but they cannot tell you a column was pointed at the wrong field. Compare the totals against the marketplace’s own GST summary the first time you use one, and fynxIQ will keep reminding you until you do.