GST Returns Offline Tool: fix Excel/CSV import errors, JSON upload and the error file

What the tool does

GSTN's Returns Offline Tool lets you prepare Form GSTR-1 or IFF (the Invoice Furnishing Facility for quarterly filers) without an internet connection, then upload the result as a JSON file. It does not file the return: after upload you still generate the summary on the portal and file it with DSC or EVC. Everything below is from GSTN's *FAQs and User Manual – Returns Offline Tool* and the portal's download page.

Install it correctly

1. Download it from gst.gov.in → Downloads → Offline Tools → Returns Offline Tool (no login needed). When we checked, the page listed version 3.2.4 for Windows 7 or later with Microsoft Excel 2010 or later, and published the file's SHA-256 — you can compare it using our SHA-256 guide.
2. Unzip gst_offline_tool.zip. Inside are the GST Offline tool.exe setup, the Section_wise_CSV_files folder, the GSTR-1 Excel Workbook Template, a Readme.txt and the user manual.
3. Run the setup and choose an install location different from the folder holding the zipped files, as GSTN advises.

Two warnings from the FAQ: uninstalling the tool deletes the data saved in it, and if you reinstall to a different location you must restart the PC, or the shortcut keeps pointing to the old path. Keep your Excel or CSV files safe before reinstalling.

Four ways to enter data

1. Manual entry in the tool;
2. import the full Excel workbook (all sections at once);
3. copy and paste from the Excel workbook;
4. import a CSV file, one section at a time.

The CSV files in the zip contain sample rows "for reference purpose only". Delete the sample data before filling in your own.

Why rows get rejected on import

GSTN lists these causes in its FAQ:

• Date format: dates in the Excel template must be dd-mmm-yyyy, e.g. 01-Jul-2017. Future dates are rejected.
• Invoice number: maximum 16 characters, letters and digits only; the only special characters allowed are / and -. No duplicate invoices.
• GSTIN: exactly 15 characters, alphanumeric, with no spaces or special characters.
• Decimals: only two digits after the decimal point.
• No negative values for value, taxable value or tax.
• HSN/SAC: numbers only.
• Wrong template: data from a home-made format is often rejected — use the template that comes with the tool.
• Wrong section selected when importing a CSV or pasting.
• Receiver GSTIN can't be your own GSTIN ("Receiver GSTIN needs to be different from Supplier GSTIN").
• B2CL threshold: from the August 2024 return period, an inter-state B2C invoice goes in B2CL only if its value is more than ₹1 lakh (₹2.5 lakh before that).
• Multi-rate invoices in B2B, B2CL, CDNR, CDNUR and EXP: enter all columns in consecutive rows.

"Invalid input" when pasting from Excel

GSTN's fix: when you copy, include the header section (the top 4 rows of the sheet) along with the header row, and copy only from GSTN's own workbook.

Rows shown in a red block

If an imported record has invalid details in a field you can't edit, the tool shows it in red. GSTN says to delete that invoice and add it again with correct details.

Re-importing overwrites

Importing again overwrites invoices with the same details. In B2CS, a line with the same place of supply and rate replaces the old one, while a new rate for the same place is added. Summary sections such as AT, ATADJ, HSN and Exempted are replaced entirely by the later upload.

Generate and upload the JSON

1. Generate the JSON in the tool. GSTN says it must not exceed 5 MB; its FAQ adds that a file of 10,000 or fewer line items can be uploaded in one go — for more, use the tool several times.
2. Log in to gst.gov.in and go to Services → Returns → Returns Dashboard, choose the period and PREPARE OFFLINE, then upload.
3. The JSON carries your GSTIN; the portal won't accept one made for a different GSTIN.

"Processed with Error": use the error file

If some records fail the portal's checks — an inactive buyer GSTIN, an invoice dated before the supplier's registration, a duplicate across periods, "Enter valid GSTIN/UIN" — the upload status shows Processed with Error.

1. Click Generate error report. GSTN says the file is ready in about 15 minutes.
2. Download it (a .zip) and open it in the Returns Offline Tool — one error file at a time.
3. Correct the flagged records, generate a new JSON and upload it again.

If the counts on the portal look wrong after upload, click Generate GSTR-1/IFF Summary to refresh the tiles.

Changes are possible only before you file the return with DSC or EVC. Download the tool only from gst.gov.in — our Returns Offline Tool page links there.