Filing outward supplies through the GST portal requires precise transmission of invoice-level details under Section 37(1) of the CGST Act. When managing sales in Tally Prime, generating a clean JSON payload skips repetitive manual entry on the portal. However, an incomplete export or unresolved master exceptions often lead to schema rejection, missing tables, or portal validation errors.
Clearing uncertain transactions in Tally Prime before export
Tally Prime segregates outward records into included vouchers, excluded vouchers, and uncertain transactions. Vouchers flagged under uncertain transactions will not appear in the generated JSON. If these entries contain uncorrected tax rates or invalid GSTINs, your outward tax liability in GSTR-1 will fall short of your accounting books.
Navigate to Gateway of Tally > Display More Reports > GST Reports > GSTR-1. Review the header block titled "Uncertain Transactions (Corrections needed)". Drill down into every exception category:
- GSTIN/UIN format errors: Occurs when party ledgers contain typographical errors or incorrect checksum characters. Correct the GSTIN directly in the exception resolution screen.
- Mismatch in country or state details: Occurs when the recipient state code conflicts with the place of supply. Verify that the POS corresponds to the first two digits of the recipient GSTIN.
- Incomplete HSN/SAC information: Every supply line requires a valid HSN or SAC code and correct tax rate classification. Assign missing tax rate tags before generating the export.
Common mistake: Exporting the JSON while vouchers sit in Uncertain Transactions. The portal accepts the file, but your B2B tables miss vital invoices, leaving buyers unable to view ITC in their GSTR-2B under Rule 36(4) of the CGST Rules.
Step-by-step export of GSTR-1 JSON from Tally Prime
Once "Uncertain Transactions (Corrections needed)" reaches zero, generate the JSON payload using the built-in export facility:
- From the GSTR-1 report in Tally Prime, press Alt+E and choose GST Returns.
- In the Export screen, set Format to JSON (Data Interchange).
- Specify the export location folder on your local drive.
- Review the period. For monthly filers, ensure the full calendar month is selected. Under GSTN GSTR-1 filing rules, monthly filers furnish outward supplies by the 11th of the succeeding month.
- Select Export. Tally Prime writes a single JSON file formatted according to the GST portal schema.
Uploading JSON on the GST portal
GSTN provides an offline upload facility so taxpayers can transmit bulk invoices without third-party connector tools. Follow the official upload path prescribed in the GSTN GSTR-1 creation manual:
- Log in to the GST portal at gst.gov.in.
- Navigate to Services > Returns > Returns Dashboard.
- Select the Financial Year and Return Filing Period, then click Search.
- Under the Details of outward supplies of goods or services (GSTR-1) tile, click Prepare Offline.
- Click Choose File under the Upload tab and select the JSON file generated by Tally Prime.
- The upload status shows "In Progress". Refresh after two minutes to verify whether the status turns to "Processed".
Upload limits: Per the GSTN Returns Offline Tool User Manual, a single JSON file upload must not exceed 5 MB in size. If your transaction volume exceeds this ceiling, export your register in segments or use the offline Excel utility.
Worked example: checking liability before portal submission
Consider Om Logistics, an outward transport and trading enterprise based in Maharashtra (state code 27). During October 2026, the company registers two major commercial outward consignments in Tally Prime.
| Invoice | Party GSTIN | Taxable value | CGST | SGST | IGST | Status in Tally |
|---|---|---|---|---|---|---|
| INV-101 | 27AAACG1111A1Z1 | ₹2,00,000 | ₹18,000 | ₹18,000 | ₹0 | Included in B2B |
| INV-102 | 24AAACH2222B1Z4 | ₹3,00,000 | ₹0 | ₹0 | ₹54,000 | Included in B2B |
Tax liability breakdown across these two invoices:
- CGST: ₹2,00,000 × 9% = ₹18,000
- SGST: ₹2,00,000 × 9% = ₹18,000
- IGST: ₹3,00,000 × 18% = ₹54,000
- Total outward tax: ₹18,000 + ₹18,000 + ₹54,000 = ₹90,000
If an operator exports the JSON before fixing an invalid state code on INV-102, Tally drops the invoice from the export. The portal JSON records only ₹36,000 in liability instead of ₹90,000. When filing GSTR-3B later, this discrepancy triggers an intimation in Form DRC-01B under Rule 88C of the CGST Rules for unexplained tax divergence.
Common upload errors and portal validation fixes
When the GST portal returns "Processed with Error", check the generated error report:
| Error message or symptom | Root cause | Resolution step |
|---|---|---|
| Processed with Error | Invalid schema format or invalid GSTIN structure | Click "Generate error report", wait 5 minutes, download error JSON, and verify failed invoice numbers in Tally. |
| Duplicate invoice number | Invoice number already uploaded in a previous session | Remove duplicate invoices in Tally Prime or delete the older draft tile on the portal before re-uploading. |
| Recipient GSTIN inactive | Buyer GSTIN cancelled or surrendered | Verify GSTIN status on the portal; convert supply to B2CS if the buyer registration was cancelled prior to invoice date. |
| File size exceeds 5 MB | High transaction volume in a single return period | Split data into batches or compile invoices through the official macro template. |
For cross-checking your inward credits against vendor filings, you can also review our guide on GSTR-2B reconciliation in Tally Prime to keep books aligned on both sides.
Frequently asked questions
Why does GSTR-1 show Processed with Error after uploading JSON from Tally Prime?
The portal marks an upload Processed with Error when structural validation fails, such as invalid state codes, duplicate document numbers, or exceeding the 5 MB file size limit. Download the error report JSON to view row-level rejection reasons.
Can an exported JSON file be larger than 5 MB?
No. Under GSTN offline upload rules, a single JSON file cannot exceed 5 MB. If your outward supplies create a larger file, split exports into batches or upload smaller date ranges.
What happens if vouchers remain under Uncertain Transactions in Tally Prime?
Vouchers retained in Uncertain Transactions are omitted from the exported JSON. Your GSTR-1 tables will underreport sales, creating mismatches against GSTR-3B and risking DRC-01B notices under Rule 88C.
Check your vendor ITC matches in browser
While GSTR-1 handles outward supplies, claiming inward ITC requires strict reconciliation with GSTR-2B. Your GSTR-2B and purchase register files are read in your browser and never uploaded to any server.
Last checked: 24 October 2026. Sources: CBIC Tax Information Portal (Section 37, CGST Act), GSTN GSTR-1 User Manual, GSTN Offline Utility Manual.