GST Returns — GSTR-1 & GSTR-3B

Filing GST returns is a monthly obligation for every regular taxpayer in India. A return is a formal declaration to the government of your sales, purchases, and the tax you owe. For a manufacturing SMB, this means compiling data from dozens or hundreds of invoices and bills — a task that is painful with spreadsheets but straightforward when your ERP already holds every transaction.

This chapter covers the two GST returns that matter most for regular taxpayers — GSTR-1 and GSTR-3B — and how Udyamo ERP Lite supports the preparation, review, and filing workflow through the GstReturn module.

What You Will Learn

• The purpose and due dates of GSTR-1 and GSTR-3B
• What data goes into each return and where it comes from in ERP
• The GstReturn model in Udyamo ERP Lite — fields, statuses, and actions
• How to review return data, file a return, and waive a nil return
• Reconciliation between your books and the GST portal
• Step-by-step: viewing return data, filing a return, waiving a nil return

Prerequisites

• GST is configured on your organization, items, customers, and vendors (Chapter 36)
• Invoices and bills have been created for the return period (Chapters 23 and 28)
• You have Owner or Admin role access

GSTR-1 — Outward Supplies

GSTR-1 is the return where you declare all your outward supplies (sales) for a given period. It is a detailed, invoice-level return.

Who files it: Every registered taxpayer except composition dealers.

Due date: 11th of the month following the tax period. For example, GSTR-1 for January is due by 11 February. (Taxpayers with turnover up to Rs 5 crore may opt for quarterly filing under the QRMP scheme, with an Invoice Furnishing Facility for the first two months of each quarter.)

What it contains:

In Udyamo ERP Lite, all of this data originates from the invoices you have created during the period. Every invoice records the customer GSTIN, item HSN codes, taxable amounts, and the CGST/SGST/IGST breakup. The system can summarize this data by tax rate, by HSN code, and by customer registration status to match the GSTR-1 format.

Tip: Ensure all invoices for the period are in "approved" or "paid" status before preparing your GSTR-1. Draft invoices should be finalized or deleted — they should not appear in your return.

GSTR-3B — Summary Return with Tax Payment

GSTR-3B is a self-declared summary return. Unlike GSTR-1 (which is invoice-level), GSTR-3B requires only aggregate figures. It is also the return through which you pay your GST liability.

Who files it: Every registered taxpayer except composition dealers.

Due date: 20th of the month following the tax period (the exact date varies by state for taxpayers with turnover up to Rs 5 crore — it can be the 20th, 22nd, or 24th depending on the state category).

What it contains:

The key calculation in GSTR-3B is:

Net tax payable = Output tax (from sales) − Input Tax Credit (from purchases)

If the result is positive, you pay the difference through the electronic cash ledger on the GST portal. If the result is negative (more ITC than output tax), the excess carries forward.

In Udyamo ERP Lite, the output tax comes from your invoices (cgst_amount, sgst_amount, igst_amount on invoices), and the input tax comes from your bills (cgst_amount, sgst_amount, igst_amount on bills). The system provides the aggregate figures you need to fill Table 3.1 and Table 4 of GSTR-3B.

The GstReturn Model in Udyamo ERP Lite

Udyamo ERP Lite tracks each return period as a GstReturn record with the following fields:

Statuses

• Pending — The return record exists but has not been filed yet. This is the initial status.
• Filed — The return has been filed on the GST portal and marked as filed in the ERP.
• Waived — Used for nil returns where there are no transactions for the period. The return obligation is acknowledged but no filing is needed (some businesses still file a nil return on the portal — the waive action in ERP simply marks the internal record).

Actions

Warning: Udyamo ERP Lite does not file returns directly on the GST portal. The ERP serves as your data preparation and record-keeping system. You must log in to the GST portal (or use a GST Suvidha Provider) to actually file the return. Once filed, you come back to Udyamo and mark the return as filed.

The Filing Workflow

The typical monthly workflow for GST return filing is:

1. Close the period. Ensure all invoices and bills for the month are finalized. No draft transactions should remain.
2. Review GSTR-1 data. Use the GST return view to see the outward supply summary — B2B invoices, B2C summary, HSN summary. Compare this with your sales register.
3. File GSTR-1 on the GST portal. Log in to the portal, enter or upload the data, and submit GSTR-1.
4. Mark GSTR-1 as filed in Udyamo. Use the file_return action on the GSTR-1 record for the period.
5. Review GSTR-3B data. Check the output tax summary (from invoices) and input tax credit summary (from bills). Calculate the net tax payable.
6. Reconcile ITC with GSTR-2B. Before filing GSTR-3B, compare your purchase-side GST with the GSTR-2B data available on the portal. Differences may arise because a vendor has not filed their return or has reported incorrect values.
7. File GSTR-3B and pay tax. Submit GSTR-3B on the GST portal and pay any net tax liability through the electronic cash ledger.
8. Mark GSTR-3B as filed in Udyamo. Use the file_return action on the GSTR-3B record.

Reconciliation Between Books and Portal

Reconciliation is one of the most important — and most time-consuming — aspects of GST compliance. There are two key reconciliation points:

GSTR-1 vs. Books. Your GSTR-1 should match your invoice register exactly. If you find a mismatch, it usually means a late invoice was issued after GSTR-1 was filed, or an amendment is needed.

ITC (Books) vs. GSTR-2B. The ITC you claim in GSTR-3B must be supported by your supplier's filings. The GST portal generates GSTR-2B (an auto-drafted ITC statement) based on your suppliers' GSTR-1 filings. If a supplier has not filed their GSTR-1, the corresponding ITC will not appear in your GSTR-2B, and you may need to defer claiming that credit.

Tip: Run the reconciliation at least a week before the GSTR-3B due date. This gives you time to follow up with vendors whose invoices are missing from GSTR-2B.

Step by Step: Viewing GST Return Data

1. Navigate to Tax & Compliance > GST Returns.
2. You will see a list of return records organized by period and return type.
3. Select the return period you want to review — for example, gstr1 for period 01-2026.
4. The system displays the summary: total taxable value, CGST, SGST, IGST, and total tax.
5. Review the underlying invoices or bills that contribute to these totals.
6. If any figures look incorrect, investigate the source transactions before proceeding.

Step by Step: Filing a Return

1. Navigate to Tax & Compliance > GST Returns and select the return record (e.g., GSTR-3B for January 2026).
2. Verify that the status is Pending.
3. Review the tax amounts: cgst_amount, sgst_amount, igst_amount, and total_tax.
4. File the return on the GST portal using the figures from Udyamo.
5. Once the portal confirms successful filing, return to Udyamo.
6. Click the File Return action on the return record.
7. The status changes to Filed and the filing_date is recorded.
8. Optionally, add a note — for example, "Filed via GST portal, ARN: AA270226012345R".

Step by Step: Waiving a Nil Return

1. Navigate to Tax & Compliance > GST Returns and select the return record for the period.
2. Verify that the return has zero transactions — total tax should be Rs 0.
3. Click the Waive action.
4. The status changes to Waived.
5. Add a note explaining why: for example, "No sales or purchases in this period — business was closed for annual maintenance shutdown."

Required: Even if you waive a return in Udyamo, you may still need to file a nil return on the GST portal. Check with your accountant.

Tips & Best Practices

• Finalize all transactions before the 10th of the following month. This gives you time to review data and file GSTR-1 by the 11th.
• Do not modify invoices after GSTR-1 has been filed. If a correction is needed, issue a credit note or debit note instead.
• Maintain a filing calendar. GSTR-1 by the 11th, GSTR-3B by the 20th. Late filing attracts a penalty of Rs 50 per day (Rs 20 per day for nil returns), plus interest at 18% per annum on the outstanding tax.
• Archive the GST portal acknowledgment (ARN) in the notes field of the GstReturn record. This creates a single audit trail — your ERP has the data, the filing date, and the ARN.
• Reconcile ITC monthly, not annually. Catching discrepancies early is far easier than sorting out twelve months of mismatches before the annual return.

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