If you're GST-registered, two returns run your compliance life: GSTR-1 and GSTR-3B. Most studio owners treat them as a monthly ritual their CA performs in a back room, numbers go in, an OTP gets entered, everyone moves on. And that works fine right up until the month it doesn't, a client's credit gets blocked because your GSTR-1 missed their invoice, or a notice arrives because your 3B and your 1 don't agree. So let me explain what these two returns actually are, in studio language, and how to set your month up so filing becomes boring, which is exactly what filing should be.
GSTR-1 and GSTR-3B in one minute each
GSTR-1 is the detail return. Every invoice you raised in the period goes in, invoice by invoice for registered (B2B) clients with their GSTIN, and as consolidated figures for unregistered (B2C) clients. This return is not where you pay anything, it's where you declare. And here's the part that makes it matter socially: whatever you file in GSTR-1 flows into your client's GSTR-2B, which is the statement their accountant uses to claim input tax credit. Miss their invoice or fat-finger their GSTIN, and their credit is stuck, and you will hear about it.
GSTR-3B is the summary and payment return. Total outward supplies, total tax due, input tax credit claimed, net cash paid. No invoice-level detail, just the aggregates, and this is where money actually leaves your bank.
The golden rule that follows from those two definitions: your 3B totals must reconcile with your 1, every single period. The system compares them, and persistent mismatch is one of the most reliable notice-generators in the whole regime.
Your filing calendar, monthly or QRMP
Which dates you live by depends on turnover. Studios up to ₹5 crore can opt into the QRMP scheme, quarterly returns with monthly payment, and honestly for most small studios it's the saner rhythm.
| Return | Monthly filer | QRMP filer (turnover up to ₹5 crore) |
|---|---|---|
| GSTR-1 | By the 11th of the next month | Quarterly, with optional IFF for B2B invoices in months 1 and 2 |
| GSTR-3B | By the 20th of the next month | Quarterly, by the 22nd or 24th depending on state |
| Tax payment | With 3B monthly | Monthly via challan (fixed sum or self-assessed) |
The IFF, invoice furnishing facility, is worth understanding if you're on QRMP with corporate clients: it lets you push B2B invoices up in the first two months of the quarter so your client's credit isn't waiting for your quarterly filing. If a builder or office client pays faster when their credit shows up, the IFF is how you keep them happy without switching to monthly.
Late filing costs real money, a per-day late fee on each return plus 18% annual interest on tax paid late, but the bigger cost is the downstream chaos: you can't file the next period until the previous one is in, and a stuck return quietly blocks e-way bills and, eventually, your registration's good standing on the official GST portal.
What a design studio's GSTR-1 actually contains
Here's where studio-specific reality enters. A typical month for a mid-size studio might include a design fee invoice to a registered builder (B2B, invoice-level entry with GSTIN), two residential clients (B2C, consolidated), a credit note because a client returned a damaged console, and an advance received against a new turnkey project. Every one of those lands in a different table of GSTR-1, and two of them trip people constantly.
The advance is the first trap. For services, GST is due when you receive the advance, not when you invoice, and advances have their own place in the return. Studios that only report invoiced amounts systematically under-declare in heavy-advance months, and I've written up the whole mechanics in GST on advances received in interior projects because it deserves the detail.
The second trap is classification. Whether a bundled deliverable is one supply at one rate or several supplies at several rates changes what lines you declare, and that's the composite-versus-mixed-supply question, which I've unpacked in composite vs mixed supply in interior contracts. Decide the classification when you quote, not when you file, because your CA can't reclassify a signed contract at 11pm on the 10th.
The reconciliation habit that prevents notices
At the end of the day, clean filing is a reconciliation habit, not a filing-day heroic. Three matches, done monthly:
The monthly three-way match
- Books to GSTR-1: every invoice and credit note in your ledger appears in the return, series unbroken
- GSTR-1 to GSTR-3B: the summary totals agree with the detail, to the rupee
- Purchases to GSTR-2B: you claim credit only on what suppliers actually filed, and chase the ones who didn't
- Bonus: quarterly, sanity-check turnover against what flows to the Income Tax portal, because the two systems compare notes
That third line is where studios lose actual money. Your plywood dealer or hardware supplier who didn't file means your credit doesn't appear in 2B, and claiming it anyway is how you buy a future demand with interest. Keep a simple rule: no supplier payment in full until their invoices show up in your 2B, and confirm the rates they charged you against an HSN/SAC code lookup when something looks off.
Making the data clean at the source
Everything above gets dramatically easier when the numbers are born clean instead of cleaned up later. The studios that suffer at filing time are the ones where quotes live in Excel, invoices get made fresh in Tally at month-end, and someone re-types line items in between, because every re-type is a mismatch waiting for the reconciliation to find it.
In Designa, the approved quote becomes the GST invoice in one click, correct SAC and HSN lines, correct CGST/SGST or IGST split, unbroken series, and it syncs to Tally or Zoho Books, so what your CA files from is literally the same data the client approved. The approval itself is timestamped in the client portal, which has saved more billing disputes than I can count, and if you haven't set that up yet, my guide on setting up a branded client portal for your studio shows how. The one-click flow is detailed in how to turn a quote into a GST invoice in minutes, and the wider monthly discipline lives in bookkeeping basics for an interior studio.
Key takeaways
- GSTR-1 declares invoice detail, GSTR-3B summarises and pays, and the two must always reconcile
- QRMP with the IFF is the sane rhythm for most studios under ₹5 crore
- Advances on services are declared when received, heavy-advance months trip everyone
- Claim credit only against GSTR-2B, and hold supplier payments until their filings appear
- Clean source data (quote = invoice = books) makes filing a non-event
Frequently asked questions
What is the difference between GSTR-1 and GSTR-3B?
GSTR-1 is the invoice-level detail of everything you billed, GSTR-3B is the summary return where you claim credit and actually pay tax. They must reconcile every period.
When are GSTR-1 and GSTR-3B due for a small design studio?
Monthly filers: GSTR-1 by the 11th, GSTR-3B by the 20th of the following month. Studios up to ₹5 crore can opt for QRMP and file quarterly with monthly tax payment.
What happens if I file GSTR-1 late?
A per-day late fee applies, your client's input credit is delayed because your invoices don't reach their GSTR-2B, and you can't file the next period until this one is in.
Do advances from clients go into these returns?
Yes. For services, GST on an advance is due in the period you receive it, and it's declared in GSTR-1 and paid through GSTR-3B for that period.
Can software prepare my GST returns data?
Yes. Designa keeps quote, invoice and payment data in one flow and syncs to Tally or Zoho Books, so your CA files from clean, reconciled data instead of re-typed spreadsheets.
Filing is a plumbing problem, and plumbing problems are solved by fixing the pipes, not by mopping faster each month. If you want to see quote-to-invoice-to-books run as one pipe, the live demo is at demo.designa.work, and the founding offer, one flat price for the whole studio, billed in rupees, is at go.designa.work.