Checklist
GSTR-3B document checklist: what clients send each month
The documents a CA firm needs from each GST client before it can prepare GSTR-3B, the due dates to plan around, and a WhatsApp message clients actually answer.
The short answer
Every month, ask each client for the sales register or sales invoices and the purchase register or purchase invoices for that month. Add bank statements, credit and debit notes, expense invoices and reverse-charge bills where they apply. Monthly filers file GSTR-3B by the 20th of the next month; QRMP filers file quarterly by the 22nd or 24th, depending on the state.
The list
Documents to collect for GSTR-3B
Two items for every client, five more where they apply, and three things the firm normally has already.
Every client, every month
- Sales register, or every outward (sales) invoice for the month, including e-invoices and the B2C summary
- Purchase register, or every inward (purchase) invoice for the month
Only where they apply
- Bank statements for the month, for every account the business uses
- Credit and debit notes issued and received in the month
- GST invoices for expenses on which input tax credit is claimed (rent, telecom, professional fees, freight, repairs)
- Bills for reverse-charge supplies, such as goods transport agency services, legal services from an advocate, or imported services
- The GSTR-2B statement, only if the firm cannot download it from the GST portal itself
Usually not asked of clients
- GSTR-2B, GSTR-1 data and ledger balances, which the firm can download from the GST portal
- Tax paid through challans, visible in the electronic cash ledger
- Input tax credit reversal workings, which the firm prepares rather than the client
Due dates
When GSTR-3B is due
Plan the collection deadline backwards from these dates. Due dates can be extended by government notification, so confirm the current month on the GST portal.
Monthly filers: the 20th
GSTR-3B is due on the 20th of the month after the tax period. GSTR-3B for September 2026 is due on 20 October 2026.
QRMP filers: the 22nd or 24th after the quarter
Taxpayers with aggregate turnover up to ₹5 crore can opt for the Quarterly Return Monthly Payment (QRMP) scheme. They file GSTR-3B once a quarter, pay tax for the first two months of the quarter through PMT-06 by the 25th of the following month, and may report B2B invoices through the optional IFF by the 13th.
22nd of the month after the quarter
Chhattisgarh, Madhya Pradesh, Gujarat, Maharashtra, Karnataka, Goa, Kerala, Tamil Nadu, Telangana, Andhra Pradesh, Daman and Diu and Dadra and Nagar Haveli, Puducherry, Andaman and Nicobar Islands, Lakshadweep.
24th of the month after the quarter
Himachal Pradesh, Punjab, Uttarakhand, Haryana, Rajasthan, Uttar Pradesh, Bihar, Sikkim, Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura, Meghalaya, Assam, West Bengal, Jharkhand, Odisha, Jammu and Kashmir, Ladakh, Chandigarh, Delhi.
The quarterly day depends on the state or union territory of the principal place of business. Sources: GST portal help: Form GSTR-3B (due dates) · CBIC: CGST Rule 61 (state-wise quarterly due dates) · CBIC Circular 143/13/2020-GST on the QRMP scheme (PMT-06 by the 25th) · GST portal FAQ: QRMP scheme and IFF (by the 13th).
How to
How to collect GSTR-3B documents from a client
Six steps that work whether you chase by hand or use software.
- 01
Fix the client's list once
Start every client on the two core items, sales and purchases. Add bank statements, credit and debit notes, expense invoices or reverse-charge bills only for clients who have them, so nobody is asked for documents that do not exist.
- 02
Set an internal deadline before the due date
For monthly filers GSTR-3B is due on the 20th of the following month, so ask for documents to arrive several days earlier, leaving time to review, reconcile with GSTR-2B and prepare the return.
- 03
Send one itemised request
Message each client once, early, naming every item and the month, for example “Sales register for September 2026”. A named list gets answered; “please send GST documents” gets ignored.
- 04
Check each file as it arrives
Confirm each file is the document you asked for, covers the right month and is readable. A bank statement for the wrong month or a duplicate should not tick an item off.
- 05
Remind only about what is missing
Follow up a few times before the deadline, name only the items still open, avoid late-night messages, and pause when the client replies.
- 06
Stop when the list is complete
When every item is received, or waived because it does not apply this month, stop reminding the client and pass the complete set to whoever prepares and files the return.
Template
A WhatsApp request clients answer
Copy it, fill in the braces and delete items the client does not have.
Hello {Client name}, for your GSTR-3B for {Month Year}, please send on this chat by {date}:
1. Sales register or all sales invoices for {Month Year}
2. Purchase register or all purchase invoices for {Month Year}
3. Bank statement(s) for {Month Year}
4. Credit/debit notes for {Month Year}, if any
Photos or PDFs are fine. Reply "none" for any item that does not apply. Thank you!With Fyliio
How Fyliio runs this checklist
Fyliio's GSTR-3B checklist is this list. Every client is asked for sales and purchases; the firm turns on bank statements, credit and debit notes, expense invoices, reverse-charge bills or GSTR-2B per client. Fyliio sends the itemised request on WhatsApp, checks each photo or PDF against the items still open, sends anything unclear to your team, reminds clients about what is missing and stops when the list is complete. Your team downloads checked, complete documents and files in the software it already uses. See the platform or how Fyliio compares with other tools.
FAQ
Frequently asked questions
What documents are required for GSTR-3B?
At minimum, the month's sales (outward supply) invoices or sales register and purchase (inward supply) invoices or purchase register. Depending on the client, also bank statements, credit and debit notes, GST invoices for expenses on which input tax credit is claimed, and bills for reverse-charge supplies. The firm usually downloads GSTR-2B from the GST portal itself.
What is the GSTR-3B due date for monthly filers?
The 20th of the month after the tax period. For example, GSTR-3B for September is due on 20 October. The government can extend due dates by notification, so confirm on the GST portal.
What is the GSTR-3B due date under the QRMP scheme?
Quarterly GSTR-3B is due on the 22nd or the 24th of the month after the quarter, depending on the state or union territory of the principal place of business: the 22nd for states such as Maharashtra, Gujarat, Karnataka and Tamil Nadu, and the 24th for states such as Uttar Pradesh, Bihar, West Bengal and Delhi. Tax for the first two months of the quarter is paid through PMT-06 by the 25th of the following month.
Who can opt for QRMP?
Registered persons with aggregate annual turnover up to ₹5 crore in the current and preceding financial year, who have filed their last due GSTR-3B. Under QRMP, GSTR-1 and GSTR-3B are filed quarterly, and the optional Invoice Furnishing Facility (IFF) for B2B invoices in the first two months is due by the 13th of the next month.
Do clients need to send GSTR-2B?
Usually not. GSTR-2B is generated on the GST portal, and a firm with access to the client's login can download it. Ask the client only when the firm has no portal access.
Is a nil GSTR-3B still required?
Yes. The GST portal's help says filing GSTR-3B is mandatory for all normal and casual taxpayers, even with no business in the tax period. The client still needs to confirm there were no sales or purchases.
How does Fyliio use this checklist?
Fyliio's GSTR-3B checklist asks every client for the sales and purchase items, and adds bank statements, credit and debit notes, expense invoices, reverse-charge bills or GSTR-2B only for clients the firm turns them on for. It sends the itemised request on WhatsApp, checks each file against the open items, reminds about what is missing and stops when the list is complete. It does not prepare or file the return.
Run this checklist on WhatsApp
We set up your firm and your GSTR-3B checklist, import your clients and run the first cycle with you.