Most disputes we see between a transport vendor and a client’s finance team are not about the money. They are about an invoice that cannot be reconciled, and the cause is almost always one of four things.
This is not tax advice — rules change and your circumstances differ, so confirm anything here with your own accountant before relying on it. But these are the four places invoices go wrong, in the order we see them.
1. Place of supply decided by hand
The split between CGST plus SGST and IGST follows the place of supply, not the address on the letterhead and not whoever raised the document. Where the supply is within a state, the invoice carries CGST and SGST. Across a state, IGST.
The failure is mundane: someone raises the invoice from a template that has CGST and SGST on it because the last one did, and a client registered in another state receives an invoice they cannot claim. It comes back, and the month’s billing slips by a week.
The fix is to derive it rather than type it. If the system knows the registered state of both parties, this stops being a decision anyone makes.
2. Reverse charge treated as an afterthought
Where the recipient accounts for the tax, the invoice is raised without GST and carries the declaration to that effect. Straightforward enough on its own.
The trap is an account whose journeys fall under different treatments in the same period. One invoice must not mix them. If some trips are forward charge and some reverse charge, that is two invoices, each internally consistent. A single document carrying both is exactly the kind of thing that gets returned.
3. The SAC code missing or wrong
Passenger road transport falls under SAC 996412. It belongs on the invoice alongside the taxable value and the tax split. It is a small field that costs nothing to get right and causes real friction when it is absent, because the recipient’s own filing needs it.
4. Numbering that does not survive the financial year
Invoice series run on the Indian financial year, April to March. Three things follow from that and are regularly missed:
- The series should restart each April, and the format should make the year
visible —
INV/26-27/0093tells you more thanINV/0093. - The counter must not move backwards. If a number was issued, it was issued.
- A withdrawn invoice does not leave a hole. A tax series with a gap in it is a question you will be asked.
What a clean corporate invoice contains
For a month of corporate transport, the document that reconciles first time carries all of this:
| Field | Note |
|---|---|
| GSTIN of both parties | Drives the place-of-supply determination |
| Period covered | Unambiguous start and end dates |
| SAC 996412 | Passenger road transport |
| Taxable value | Before tax, matching the sum of the trips |
| Tax split | CGST + SGST or IGST, never both |
| Purchase order reference | Where the client requires one, this is what gets it paid |
| Amount in words | In Indian numbering |
| Supporting trip records | One signed duty slip per journey billed |
That last row is what turns a query into a five-minute answer. When a client’s finance team asks about one line on a 148-trip invoice, either you can produce the signed record for that journey or you cannot.
The practical point
None of this is difficult. It is just detailed, and detail applied by hand once a month by whoever is free is detail that will eventually be wrong.
If you want to see how the whole month runs — duty slips raised as trips complete, then consolidated into one invoice per client with the tax handled — that is on our corporate billing and GST invoicing page, and the trip sheets page covers the records underneath it.