The GST portal produces a specific kind of frustration: the error tells you something failed without telling you what, and it usually happens on the 11th or the 20th when there is no time to investigate.
GST portal failures group into five kinds: authentication failures at submission, validation errors inside a return, e-invoice IRN rejections, portal load errors around due dates, and blocks arising from your own compliance status. Only two of those are fixed by retrying.
Blocked on a filing deadline? WhatsApp us the exact error and we will tell you which kind it is.
Quick Summary — Five Kinds
| Symptom | Kind | Fix |
| EVC or DSC fails at submit | Authentication | Check registered mobile, DSC validity, browser |
| Return will not validate | Data validation | Correct the flagged field, not the whole return |
| IRN generation rejected | E-invoice validation | Read the code, fix the invoice field |
| Page times out, error after load | Portal load | Retry off-peak, do not resubmit blindly |
| Filing blocked entirely | Compliance status | Earlier return, suspension or validation issue |
💡 TaxKitab Tip:
Before assuming an error is the portal, check whether you are blocked rather than broken. GST has several mechanisms that stop you filing for reasons unrelated to the file in front of you — an earlier period not filed, a suspended registration, unvalidated bank details. Those produce messages that read like technical failures, and no amount of retrying clears them. Two minutes on your dashboard checking return status and registration status saves an afternoon of reloading. — From our GST Filing Mistakes Guide (Book 1). Available at taxkitab.com/books (Rs 179)
Authentication Failures at Submission
The return is prepared, submission fails at the last step.
With EVC, the usual cause is the OTP going to a mobile or email that is no longer current in the registration, or an OTP that expired while the page sat open. Check the contact details on the registration rather than assuming the message did not arrive.
With DSC, the usual causes are an expired certificate, the emSigner utility not running, or a browser that no longer supports the plugin. DSC issues cluster after certificate renewals and after browser updates.
Where the authorised signatory has changed and the registration was never updated, submission will fail regardless of the certificate.
Validation Errors Inside a Return
The portal rejects the return and names a field or a table.
These are almost always real data problems rather than portal faults. A GSTIN that does not validate, a tax amount that does not reconcile to the taxable value, an HSN code of the wrong length, a place of supply inconsistent with the GSTIN, or a date outside the period.
Read the field the portal names and correct that. The instinct to rebuild the whole return usually reintroduces the same error.
Where the rejection concerns a summary that will not match, check whether the underlying data was amended after the summary was generated.
E-Invoice IRN Rejections
The IRN system returns specific codes with a specific meaning, and it is stricter than the return filing modules.
Common causes: a duplicate invoice number for the same GSTIN and financial year, an invoice date outside the permitted reporting window, a recipient GSTIN that is cancelled or invalid, a mismatch between line values and the invoice total, or a document type that does not match the content.
Duplicates deserve particular attention. An invoice number reused across a financial year will be rejected, and this is the most common cause of a sudden failure in a system that was working.
Portal Load Errors
Around the 11th and the 20th, the portal slows and sessions time out.
The correct response is to wait rather than to resubmit. Repeated submission of the same return during a timeout can create duplicate entries that are harder to unwind than the original delay.
Check the ARN before retrying. If an ARN was generated, the filing went through even though the confirmation did not appear.
When You Are Blocked Rather Than Broken
Some failures are the system working as intended.
An earlier return not filed blocks the current one, because GST returns are sequential. A suspended or cancelled registration blocks filing entirely. Unvalidated bank details can freeze operations on the registration. And input tax credit that does not appear is usually a supplier reporting issue rather than a portal fault.
None of these clear by retrying. Check your dashboard for return status and registration status before troubleshooting anything technical.
Working Through It
Read the exact message and note whether it names a field. Check your dashboard for blocks. If it names a field, fix that field. If it is generic, retry once off-peak. Check whether an ARN or IRN was generated before resubmitting anything. Then, if it persists, raise a grievance with the ARN, the exact message and a screenshot.
And file early. Most of these problems are survivable on the 5th and critical on the 20th.
Frequently Asked Questions
My EVC OTP is not arriving. What now? Check the mobile and email recorded against the registration rather than the ones you use day to day. OTPs go to the registered details, which are often out of date.
The IRN was rejected as a duplicate. Why? An invoice number cannot repeat for the same GSTIN within a financial year. Check whether the number was already used, including by a cancelled document.
The portal timed out after I submitted. Should I file again? Check for an ARN first. If one exists, the return was filed and resubmitting risks a duplicate.
Why can I not file this month’s return? GST returns are sequential. An unfiled earlier period blocks the current one. Check your return dashboard.
My input tax credit is missing. Is that a portal error? Usually not. Credit appears based on what your supplier has reported. If they have not filed, it will not show.
My DSC stopped working after a browser update. What do I do? Confirm the certificate is still valid, that the signing utility is running, and that the browser still supports it. DSC failures cluster after updates and renewals.
References
- CGST Act, 2017 and CGST Rules, 2017 — return filing and e-invoicing provisions
- GST portal user guidance on EVC, DSC and return validation
- E-invoice system documentation on IRN generation and error codes
⚠️ Portal behaviour, error codes and validation rules change with GSTN releases. Verify against the GST portal or with your advisor before relying on any step here.
Related Reading: E-Invoice IRN Generation Errors and How to Fix Them · GSTIN Suspended for Bank Account Validation: Fix It · GSTR-3B vs GSTR-1 Mismatch: Causes and How to Fix It
Call or WhatsApp: +91 7448200422 Email: info@taxkitab.com See our GST Return Filing service, or explore Managed Compliance if you want the whole calendar handled.
