Cancelling an e-way bill vs cancelling an e-invoice (IRN)

Under the e-way bill system’s validations, an e-way bill can be cancelled by the generator of the e-way bill only, and within 24 hours of its generation.

After that the system answers error 728. In live use its message words the limit as 24 hours “from Part B entry”, while the documented rule says generation, so do not count on a late cancellation working. If you create e-way bills while testing, cancel them in the same session.

• The IRN can be cancelled within 24 hours of its generation.
• It cannot be cancelled if a valid, active e-way bill exists for the same invoice.
• The cancellation can be done by active or suspended taxpayers.

Both cancellations take a one-digit reason code, but the meanings of 2 and 3 are swapped:

The IRN cancellation also takes a remark of up to 100 characters. A lookup table shared between the two will mislabel half of the cancellations, and nothing will report an error.

Because an IRN cannot be cancelled while a valid e-way bill exists for the invoice, an invoice that has both is cancelled in two steps: the e-way bill first, then the IRN.

Each window runs from its own start, so the practical deadline is the end of the IRN’s 24 hours. The e-way bill has to be cancelled, and then the IRN, before that.

If the e-way bill is already past its 24 hours and still valid, the two rules together mean the IRN cannot be cancelled either. This is a combination of the two documented rules, not a case the system’s pages discuss. As far as we know the invoice is then corrected another way, such as a credit note, which is an accounting step rather than an API call.

POST /v1/ewaybill/cancel takes ewaybill_no, cancel_reason_code and cancel_remark, with the e-way bill API username and password. POST /v1/einvoice/cancel takes irn, cancel_reason and cancel_remark, with the e-invoice API username and password.

The two portals have separate API users, even for the same GSTIN. Each call costs 3 credits on success. A refused request costs nothing, and "test_mode": true returns a sample response for free.