Annexure B JSON upload errors: find the failing step

First identify whether the error happened in Excel, during file upload, or after portal document validation. The correction and the rows you upload again depend on that stage.

This guide describes official instructions checked on 11 September 2026. It does not claim a particular live portal bug has been reproduced. Statement 3 contains export records; Annexure B contains inward-supply records. Confirm which upload you are fixing before changing anything.

Save the evidence before retrying

Keep the original workbook, generated filename, error report, screenshot, time, refund category and selected period. Record the utility version from its Read Me. Work on a copy so you can compare the correction with the failed attempt.

1. Excel will not validate or generate JSON

Check the failing row against the original invoice and the downloaded utility’s instructions:

Check	What to correct
Header	Applicant GSTIN and From/To periods must match the application; use mmyyyy
Document number	Annexure B permits up to 16 characters; investigate a longer source number instead of arbitrarily truncating it
Dropdown values	Copy the exact available option; a similar phrase may fail
Duplicate	Check GSTIN, invoice number, date, input category and HSN/SAC together; preserve genuinely separate classifications
HSN/SAC	The utility accepts 4, 6 or 8 digits; verify the actual classification
Supply type	Respect automatically disabled fields; imported services and unregistered RCM do not need a fabricated 2B period
Amounts	Required eligible/ineligible amounts need an entry, including zero where appropriate; a disabled field is different from a required blank

These are documented checks, not permission to alter the underlying transaction. See the GST portal’s Annexure B instructions and GSTN’s 18 May 2026 advisory.

For example, changing a foreign-service purchase to a domestic category to enable a field creates a classification error. Correct its supply type and supporting documents using the Annexure B example.

2. Excel passes, but the file upload fails

Compare the JSON’s originating workbook with the application GSTIN and period. Correct the workbook and regenerate JSON. Preserve the generated filename and contents; manually editing JSON or renaming a file is not the advised repair. For multiple files, use the utility’s generation sequence and unique generated names. GSTN advisory.

Keep one upload log with filename, row count and result. This catches an old export being uploaded after a workbook correction.

3. Which rows must you upload again?

The current Annexure B manual distinguishes three situations:

Portal stage	Replacement scope
Initial file upload fails and produces an error report	Correct the source and regenerate the entire statement
After Validate Statement, an Invalid Document report identifies errors	Correct and upload only the error documents
Statement validates without errors, but you need to change it	Delete the whole statement, then upload its corrected replacement

Match the instruction to the screen you reached. Save accepted records before replacement. GST portal: upload and validation workflow.

A 2B mismatch needs a source check; use the 2B-period guide. A portal-valid row can still lack refund eligibility.

4. Splitting Annexure B into several files

The supplied Annexure B utility v1.0 documents 10,000 rows per file and 250,000 per application, corresponding to up to 25 files. Enter the claim’s reversals only in the final utility file; use zero reversals in preceding files. The final file can consequently show a negative local net amount; the portal recomputes the combined result. GSTN advisory and utility download instructions.

Before proceeding, reconcile combined row counts, tax heads and reversals against your working. Repeating the full reversal in every file reduces the total more than once.

If the documented checks do not resolve the failure, retain the error evidence for a GSTN support request. For Statement 3 data preparation, use the export invoice and receipt example.