IRP error 2150: Duplicate IRN
What the IRP says
Why it happens, in NIC's words
Attempting to register a document again which is already registered and IRN is generated
What NIC says to do
Don't fire the same request siimultaneously. This results in one request giving the error as 'Duplicate IRN request'. Best way to avoid firing of IRN request repeatedly for the same request, is update in your system with IRN number when the response comes back. Next time check the IRN, if it is not there, then fire for IRN.
NIC's wording, from its published list of IRP errors, as read on 1 October 2026.
In plain words
The IRP has already registered this document and given it an IRN. One document can have only one IRN: the IRP identifies a document by the supplier's GSTIN, the document type, the document number and the financial year. If the earlier IRN was cancelled, the IRP raises a different error, 2278, and the same document number still cannot be registered again.
How to fix it
- Do not send the request again. NIC's text describes one cause: the same request sent twice at the same moment, where one of the two gets this error.
- Find out whether an IRN exists for the document, for example with NIC's "Get IRN details by Doc. Details" API, and save it against the invoice in your software.
- If this is a different invoice that carries a document number already registered in this financial year, the IRP does not register it under that number. What to do about an invoice that has already been issued is for your accountant.
Can you catch it before you upload?
No. Only the IRP knows which document numbers it has already registered.
Free, with no sign-up. The file is checked in your browser and never leaves it. A clean result does not mean the IRP will accept the invoice.