A practical guide to gstr 1: what the returns need, the month-end sequence that works, and why a clean invoice on the 3rd is worth an hour on the 10th.
The returns, and what each one is for
GSTR-1 is the statement of outward supplies — what you billed, to whom, with what tax. It is the return your customers depend on, because what you report here is what shows up in their input credit.
GSTR-3B is the summary return with the net tax position and the credit claimed, filed alongside payment.
GSTR-2A and 2B are not filed by you at all. They are what your suppliers reported about you, and reconciling your purchases against 2B is what decides how much input credit you actually get.
GSTR-9 is the annual return, which is mostly a consolidation of what was already filed — and painful in exact proportion to how loose the monthly filings were.
Due dates vary by return, by turnover and by whether you are on a monthly or quarterly scheme, and they have been revised more than once. Check the portal for the dates that apply to you.
GSTR-1: the one your customers depend on
GSTR-1 is the statement of outward supplies — every invoice you issued, to whom, at what value, with what tax. It is the return that matters most to everybody else, because what you report here is what appears in your customers' input credit. File it wrong and their claim fails, and they will come back to you.
It is assembled rather than calculated, which is why it is more work than it looks. B2B supplies are reported invoice by invoice with the customer's GSTIN; B2C goes in as a summary, with larger inter-state supplies to unregistered persons treated separately. Credit and debit notes, exports, nil-rated and exempt supplies, advances and the HSN summary each have their own tables.
So the three fields that decide how hard this is were all set at billing time: the customer's GSTIN, the place of supply, and the HSN against each line. A missing GSTIN silently moves a supply into the B2C summary. A wrong place of supply reports it in the wrong state. A blank HSN means the summary table cannot be built at all.
Whether you file monthly or quarterly depends on turnover and on the scheme you have opted into, and the due dates have been revised more than once — take them from the portal rather than from any page.
What Billixo does for return time
- Mandatory fields cannot be skipped. GSTIN, place of supply, HSN and the tax split are captured on the invoice, not reconstructed later.
- Tax split derived, not chosen. Inter-state is IGST because the customer’s state says so, not because someone picked it.
- A consecutive invoice series issued centrally, restarting each financial year — no gaps, no duplicates, whoever is billing.
- GSTR-1 summary of outward supplies, B2B and B2C separated, with the HSN summary.
- GSTR-3B summary of the net position.
- Credit and debit notes that reference the original invoice properly.
- Exports in CSV, Excel and JSON that a practitioner can open without repairing the file.
- Everything scoped to a period, so a month can be closed and looked at again later without ambiguity.
A month-end sequence that works
- On the 1st, stop billing into the closed month. A cut-off that everyone respects removes more problems than any software feature.
- Check the invoice series for the month — no gaps, no duplicates, and the last number continues into the new month.
- Review B2B invoices for a missing or malformed GSTIN. These are the ones that cost your customer credit.
- Review anything billed to another state and confirm it carries IGST.
- Confirm every line has an HSN or SAC.
- Download the GSTR-1 summary and reconcile the total to your own sales figure for the month.
- Reconcile purchases against the downloaded GSTR-2B, and chase suppliers who have not filed.
- Hand the summaries to whoever files, with the reconciliation working file attached.
What your CA actually wants from you
Not access to your software. A complete, correct outward supply summary in a file they can open, and a purchase list that reconciles to 2B.
The most common complaint from practitioners is not that a client uses the wrong product. It is that the data was never captured — GSTINs missing, place of supply guessed, HSN blank — and no amount of skill at the filing end recovers that.
A billing system that makes those fields unavoidable is worth more to your accountant than one with better reports.
Late filing, and why it compounds
Late fees and interest are the visible cost. The larger cost is that a late GSTR-1 delays your customers’ input credit, and business customers notice.
The other compounding effect is internal: a month that was not closed properly makes the next month harder to close, because you are now reconciling two. Three months of that and the annual return becomes a project.
Closing on time is mostly about the data being ready on the 1st, which is a billing problem, not a filing one.
CGST, SGST and IGST — worked out, not chosen
Whether a sale attracts CGST and SGST or IGST is not a preference. It follows from the place of supply: same state as your registration means the tax splits into central and state halves, a different state means one integrated tax at the combined rate.
That sounds simple and goes wrong constantly, because it is a dropdown in most billing software and a dropdown is something a tired person clicks past. In Billixo the split is derived from the state on the customer record against the state on your registration, and it changes the moment either does.
The consequence of getting it wrong is real: an IGST invoice raised as CGST/SGST has to be credited and reissued, and if the return has already gone in, amended.
HSN and SAC codes, and how many digits you need
Every line on a tax invoice needs an HSN code for goods or a SAC for services. How many digits depends on your aggregate turnover in the preceding financial year — smaller businesses report fewer digits than larger ones, and B2B and B2C invoices are treated differently.
Because the requirement is tied to turnover and has been tightened in stages, the practical answer is to store the fullest code you can against each product once, and let the software report at the level required. A six-digit code can always be truncated; a two-digit one cannot be expanded.
Billixo keeps the code on the product record and carries it onto every line automatically, and its AI HSN lookup will suggest one from a plain description when you genuinely do not know.
Bill scanning, in practice
The single largest time cost in most small businesses is not raising invoices — it is entering purchases. A photograph of a supplier bill goes in and a structured draft comes out: supplier, GSTIN, line items, rates, tax split and total.
You check it. That is the workflow, and it is deliberate: an extraction you did not read is a liability, not a saving. But checking a filled form takes fifteen seconds and typing one takes three minutes, and that difference compounds over a month of purchases.
A note for accountants and CAs
If you are the person who has to make sense of a client’s billing at the end of the month, what you need from their software is narrow and specific: a complete outward supply summary, correct place-of-supply treatment, HSN present on every line, and an export you can open without repair.
Billixo produces GSTR-1 and GSTR-3B summaries and exports to CSV, Excel and JSON. Client-side, the invoice fields cannot be skipped, which removes the category of problem where the data was never captured in the first place.
The price, plainly
Free is ₹0 and stays ₹0. The paid plans are bought for a fixed term, paid once, with no auto-renewal and no card kept on file — when a term ends the account drops back to Free until you decide to buy again.
There is no per-invoice charge, no per-user surprise on the free plan, and no feature that is technically included but practically throttled. What the plan says you get is what you get.
Compare the plans on the home page, or just start free now and look at the ceiling from the inside.
Reliability, backups and getting your data out
Cloud billing software is only as good as its worst day. Two things matter more than any feature list: that your data is backed up somewhere you can reach, and that you can export it in a format something else can read.
Exports here are CSV, Excel and JSON, on every plan including the free one, covering customers, products, invoices and payments. That is the honest test of whether software respects you — not what it promises, but what it lets you take when you leave.
Frequently asked questions
Can I still use my existing filing software?
Yes. The export is a file, so it hands off to any filing tool or practitioner. Change only the part that is costing you time.
How far back can I fix a mistake?
Corrections are made by credit or debit note referencing the original invoice, and the adjustment has to be declared within the statutory window — broadly, by the relevant return of the following financial year or the annual return, whichever is earlier. Past that the commercial correction stands but the tax adjustment does not.
Does Billixo file my GST returns?
No — it prepares them. GSTR-1 and GSTR-3B summaries are produced from your invoices and exported for filing on the portal or by your practitioner. The filing and the responsibility for it stay with you, which is where they legally sit.
Is my data shared with anyone?
No. It sits in this installation, scoped to your company. AI requests only happen when you explicitly ask for one, and nothing is sent anywhere otherwise.
Is it really free?
Yes. The Free plan is ₹0, needs no card and has no expiry. It has volume limits and leaves out the paid conveniences — watermark-free PDFs, GST return exports, the AI features, extra logins — but the invoices it produces are real GST invoices, and you can export your data from it whenever you like.
See it working on your own bills
The fastest way to judge billing software is to bill with it. Photograph one supplier invoice, raise one sales invoice, and look at the PDF your customer would receive.
Open the software demo → — free account, no card, about a minute to set up.
More details on the home page → — what it does, what it costs, and where the limits are.
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