You file GST returns from ERPNext by installing the free, open-source India Compliance app, generating the GSTR-1 and GSTR-3B reports straight from your sales and purchase data, reconciling against the portal, and uploading or filing through its built-in GST API integration. The invoices you already booked become your return.
Short answer
ERPNext handles GST return filing through the India Compliance app. It generates GSTR-1 from your Sales Invoices and GSTR-3B from sales plus purchase data, compares both against the GST Portal, and lets you upload or file directly using GSTN's Returns API with OTP authentication. No re-keying, no separate billing tool.
I am Manoj, an ERPNext implementation consultant at Mith Tech in Bengaluru, and I set up GST filing workflows for Indian SMBs almost every month. The pattern I see is always the same: businesses keep books in one system, then re-type everything into a filing utility. Honestly, the biggest win of filing from ERPNext is not speed, it is that your return finally matches your ledger, because both come from the exact same invoices.
What is the India Compliance app and why do you need it?
India Compliance is an open-source Frappe app, maintained by Resilient Tech, that adds GST features to ERPNext. Installing it pre-configures GST tax ledgers, HSN and SAC codes, and Item Tax Templates, then unlocks GSTR-1, GSTR-3B, e-invoicing and e-way bill generation from your existing transactions.
Plain ERPNext records tax on invoices, but it does not know Indian return formats or talk to the GST Portal on its own. India Compliance bridges that gap. It maps your booked GST into the government's return schemas and, once you configure GST API credentials, connects to GSTN's services so you can fetch, upload, and file data.
Because both ERPNext and India Compliance are open source, there is no per-return or per-user licence fee for the software itself. GST portal charges and any GSP fees are separate statutory or vendor matters; check the official GST portal for those. What you get is a filing pipeline that lives inside the same system as your accounting.
I always tell clients: the app is only as good as the invoice discipline behind it. Correct GSTINs, correct place of supply, correct HSN codes on every line. Get those right at data entry and the returns almost write themselves.
Skimmable summary: India Compliance is the free, open-source app that turns ERPNext transactions into filable GST returns and connects to the GST Portal.
How do you generate GSTR-1 from ERPNext?
GSTR-1 is the outward-supply return, and in ERPNext it is built entirely from your Sales Invoices for the period. Open the GSTR-1 (Beta) tool, choose the company and return period, and generate. The app groups every taxable sale into the correct GSTR-1 sections automatically.
Before your first filing, spend time in GST Settings. Set your filing frequency to monthly or quarterly, enable "Compare Data with GST Portal" if you want API reconciliation, and turn on "Restrict Changes to Transactions After Filing" so nobody edits an invoice after the return is locked.
Configure GST Settings
Enter your GST API credentials for the Returns service and enable API access on the GST Portal side. Choose monthly or quarterly frequency to match your turnover profile.
Generate the report
Open GSTR-1 (Beta), select company and period, and click Generate. The process is queued and may request OTP authentication for any API operation.
Review the tabs
Check the section tabs, the net output GST from your ledgers, and the filing-status indicators. Drill into any figure that looks off and fix the source invoice.
Compare with the portal
Use the compare feature to check your unfiled data against GST Portal records. The app highlights mismatches so you resolve them before uploading.
Upload, then file
Click Upload to transmit data, clear any errors in the Error tab, review the summary, then File using your authorised PAN and OTP. Status moves to Filed and final data downloads back into ERPNext.
You can also export GSTR-1 as JSON or Excel if you prefer to upload through the portal offline utility instead of the API. Both paths use the same generated data.
Skimmable summary: Generate GSTR-1 from Sales Invoices in the GSTR-1 Beta tool, compare against the portal, then upload and file with OTP or export JSON.
How does ERPNext generate GSTR-3B?
GSTR-3B is the summary return covering output tax liability and input tax credit, and ERPNext builds it from both your sales and your purchase transactions. Navigate to Accounting, then Goods and Services Tax (GST India), then GSTR-3B Report. Create a new report, enter company, GSTIN, year, and month or quarter, and save to produce the form.
The report has two halves that matter. Outward liability comes from your sales, mirroring what you reported in GSTR-1. Input tax credit comes from your Purchase Invoices, governed by an ITC Claim Period setting that decides when credit on each purchase is claimed.
That ITC Claim Period is the feature most people miss. The app auto-sets it from posting dates and GSTR-2B availability, but you can override it manually when a supplier's invoice lands in your books in a different month than it appears in your GSTR-2B. Reverse-charge liability follows the posting date, while inward reverse-charge credit follows the claim period.
Use View Form to see the formatted GSTR-3B, and the GSTR-3B Details Report to audit every purchase transaction feeding the return. Once you file for a period, the ITC claim period for that period locks, so reconcile before you commit.
GSTR-3B outward tables are now hard-locked
Following a GSTN advisory in 2025, the outward-liability tables in GSTR-3B are auto-populated from your GSTR-1 and are no longer editable on the portal for that period. If your GSTR-1 is wrong, you cannot quietly fix it in GSTR-3B anymore. This makes accurate GSTR-1 data from ERPNext more important than ever.
Skimmable summary: GSTR-3B is generated from sales and purchase data, with an ITC Claim Period setting controlling when credit is taken; outward tables now flow locked from GSTR-1.
How do you reconcile before filing?
Reconciliation means matching three things before you file: your books, your GSTR-1, and the credit the portal says you are entitled to in GSTR-2B. Skipping it is the single biggest cause of mismatch notices and blocked input tax credit for Indian SMBs.
GSTR-2B is the auto-drafted input-tax-credit statement generated for you around the 14th of each month from your suppliers' filed GSTR-1 data. Your job is to confirm that the credit you claim in GSTR-3B genuinely appears in GSTR-2B, because credit not reflected there is credit you may not be allowed to take.
Since late 2025, the Invoice Management System (IMS) sits at the centre of this. On the portal you now Accept, Reject, or keep Pending each B2B invoice, debit note, and credit note before it flows into your GSTR-2B and then GSTR-3B. Treat IMS as the gate: what you accept becomes your claimable credit.
| Reconciliation check | What you compare | Why it matters |
|---|---|---|
| GSTR-1 vs books | ERPNext Sales Invoices vs generated GSTR-1 | Confirms every sale is reported correctly |
| GSTR-1 vs GSTR-3B | Outward liability in both returns | They must agree, since 3B now auto-fills from 1 |
| GSTR-3B ITC vs GSTR-2B | Claimed credit vs portal statement | Prevents claiming credit you cannot support |
| Purchases vs IMS | Booked purchases vs accepted invoices | Ensures supplier invoices are actioned in IMS |
India Compliance includes a GST Reconciliation tool that matches your purchase records against downloaded GSTR-2B data, flagging invoices that are missing, mismatched, or only on one side. Run it every month before touching GSTR-3B.
Skimmable summary: Reconcile books, GSTR-1, and GSTR-2B before filing, use IMS to action supplier invoices, and lean on the app's GST Reconciliation tool for purchases.
What changed for GST filing in 2025-2026?
Several structural changes reshaped GST filing recently, and all of them reward clean ERPNext data. The theme is simple: the portal is removing your ability to manually patch returns, so upstream accuracy is now the whole game.
The three shifts that matter most for anyone filing from ERPNext:
GSTR-3B hard-locking
Outward-liability tables auto-populate from GSTR-1 and are non-editable on the portal. Your GSTR-1 must be right the first time.
GSTR-1A correction window
GSTR-1A became the route to fix same-period GSTR-1 errors. It opens after GSTR-1 is filed and closes when GSTR-3B is submitted for that period.
IMS and ITC direction
IMS invoice actioning drives your GSTR-2B, and authorities have signalled that input-tax-credit locking is the next phase on the roadmap toward mid-2026.
For ERPNext users the practical response is unchanged in spirit but stricter in execution: enter GSTINs, place of supply, HSN codes, and reverse-charge flags correctly, file GSTR-1 early enough to use the GSTR-1A window if needed, and reconcile GSTR-2B every month. The India Compliance app keeps pace with these changes through its releases, which is one reason I keep clients on current versions.
If you also need e-invoicing wired up, that feeds GSTR-1 too, and I covered the full setup in the e-invoicing setup guide. For a broader compliance checklist, see the ERPNext GST 2026 readiness guide.
Skimmable summary: Hard-locking, GSTR-1A, and IMS mean upstream accuracy in ERPNext now decides your filing outcome; keep India Compliance current and reconcile monthly.
Frequently asked questions
Is the India Compliance app free?
Yes. India Compliance is open source, like ERPNext and Frappe. There is no per-return or per-user software licence fee for the app itself. Separate GST portal or GST Suvidha Provider charges for API access are statutory or vendor matters; check the official GST portal or your GSP for those. What you avoid is a separate paid filing tool.
Can I file GSTR-1 directly from ERPNext without the portal?
You can file GSTR-1 through the app once GST API credentials are configured, using GSTN's Returns service with OTP authentication. The upload and file actions happen inside ERPNext. If you prefer, you can instead export JSON or Excel from the same generated report and upload it through the GST Portal's offline utility.
What are the GSTR-1 and GSTR-3B due dates?
GSTR-1 is generally due by the 11th of the following month for monthly filers, or the 13th after the quarter for QRMP quarterly filers. GSTR-3B is generally due by the 20th of the following month, with quarterly dates of the 22nd or 24th depending on state. Always confirm the current calendar on the official GST portal, since dates can be extended by notification.
Does ERPNext handle GSTR-2B reconciliation?
Yes. India Compliance includes a GST Reconciliation tool that downloads GSTR-2B and matches it against your Purchase Invoices, flagging missing, mismatched, or one-sided entries. This is essential now that GSTR-3B input tax credit must align with GSTR-2B, and now that IMS actioning determines what appears in your GSTR-2B in the first place.
What happens if I edit an invoice after filing?
If you enabled "Restrict Changes to Transactions After Filing" in GST Settings, ERPNext blocks edits to Sales Invoices once GSTR-1 is filed, protecting return integrity. For genuine corrections, use the GSTR-1A window for same-period fixes before GSTR-3B, or amend in a later period's return following normal GST amendment rules.
Do I need e-invoicing before I can file GSTR-1?
Not necessarily, but if your turnover crosses the e-invoicing threshold, e-invoices feed directly into GSTR-1, reducing manual entry. India Compliance handles e-invoice and e-way bill generation alongside returns. Whether or not e-invoicing applies to you, GSTR-1 is still generated from your Sales Invoices in ERPNext.
About the author
I am Manoj, an ERPNext implementation consultant at Mith Tech, an independent open-source ERPNext and Frappe studio based in Bengaluru. I set up GST-compliant ERPNext systems for Indian SMBs, wiring India Compliance, e-invoicing, and return-filing workflows so that books and returns come from a single source of truth. I write these guides from live implementation work, not theory.
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