A composition invoice still looks like a bill. It is not ITC.

Acme Steel Fittings. 14 employees. Annual turnover about 90 lakhs. They sell mild steel rounds from a shed in MIDC. You buy from them every month. Their accountant runs composition because they are under the threshold. They print bills on A4 with a faint rubber-stamp GSTIN. The bill has a total: ₹40,000 for MS rounds. No tax breakup. No CGST, no SGST. Just a rupee amount.

You scan it on a Monday. The extractor pulls the GSTIN: 27AAPFU1234A1ZF. It passes checksum. It passes format. It looks like a GSTIN should look. A confidence score might even say 94% on the total. The trap is not in the number. It is in the blank tax columns.

Composition is a GST scheme for eligible small taxpayers. Whether Acme qualifies depends on their turnover and whether they opted in. The current limits, rates, and who may be excluded live on CBIC and the GST portal. Those numbers change. I will not paste a crore slab here as if it were eternal law. Look it up the week you draft this, not the week you copied the number from someone else's blog.

What does not change: composition dealers do not charge CGST and SGST the way a regular supplier does. The tax treatment is different. The bill still arrives in your WhatsApp group. The photocopy still needs to become a Tally voucher. But the voucher is an expense, not a credit, unless the CA says otherwise.

The OCR trap

The page has a faint grid: description, qty, rate, amount, and then empty CGST and SGST columns because the supplier never fills them. Total: ₹40,000. A vision model has seen ten thousand regular invoices with filled tax columns. It writes 9% and 9% into the empty boxes, or it keeps ₹40,000 as the total and fakes the tax to close the math. Either way, you now have a GSTIN that passes checksum, an arithmetic that closes, and a tax claim that is fiction.

The trap is that the gate may pass. If the model filled in the tax and the total still matches the printed grand total, validate_invoice sees numbers that add up. It does not know that the paper had blank tax columns. It does not know the supplier is composition. It knows only what it was given, and what it was given now has fabricated tax.

That is why composition belongs in the process, not in the product. The clerk who knows Acme is composition should not type 9% to "make it export." They should post the path the CA uses for composition purchases: no ITC ledgers, no credit claim, just the expense. If we force it through the GST path to clear the queue, we have lied to Tally.

What the clerk should do

If the header says "composition" or "composition taxable person," or the tax columns are blank, or the total has no GST breakup: stop. Do not fill in tax to make the export clean. Pin the GSTIN in a spreadsheet or in Tally master notes. Next time that supplier sends a bill, the review queue knows: this is an expense, not a GST purchase with credit.

Open the GST portal. Enter the GSTIN from the scan. Read the legal name and the scheme status. If the portal says composition, the blank tax columns are correct. If the portal says regular, the supplier may have left composition mid-year. Period matters. The Act and notifications govern the switch. We will not date it. Check the portal as of the invoice date, not as of the day you scanned the WhatsApp photo in April.

Two traps beyond composition. First: unregistered suppliers who send a bill with no GSTIN at all. Required buyer and seller GSTIN are both required fields. No GSTIN means no auto-export. That is the correct failure. Do not paste a neighbour's GSTIN so the row exports. Second: RCM. Reverse charge is a different brief. A supply from an unregistered person under RCM has its own ITC story. Do not stuff RCM into this page or into this invoice. Read the section 16 and IRN posts for the statutory overlay.

A desk that buys from both

Most factories have a mix: regular GST suppliers and a tail of composition or unregistered. The regular pile is the gate. The composition tail is a short list of GSTINs the accounts head already knows. Put that list next to the review queue. When one of those GSTINs appears, do not "fix" blank tax. Voucher it the way the CA already does.

If a known composition GSTIN comes through with a full CGST/SGST breakup that checksums and closes, believe the paper enough to review, not enough to auto-export ITC. The supplier may have left composition. Portal status is the tie-break. Checksum will not tell you they opted out last quarter.

Tally

Follow Tally Help and your CA for how composition purchases are vouchered. We export Tally-import files for validated GST invoices. A composition bill that should not carry tax should not be forced through that path just to clear a queue. Ledger names still have to match. That problem does not go away because the tax is zero.

If you post it as a regular GST purchase "so it imports," you will spend 2B week reversing ITC you never had. That cost is not a clerk's salary. It is amendment time. See cost for why we refuse labour-replacement theatre. The CA will also ask: did you claim ITC? If yes, on which voucher, and is the supplier composition on the portal for that period? Did 2B show a line? It should not, in the ordinary story. Bring the scan. Bring the portal screenshot. Do not bring a confidence score.