GSTR-3B Filing: Step by Step Process for 2025

What is GSTR-3B?

GSTR-3B is a self-declared summary return that every regular GST-registered taxpayer must file monthly or quarterly. Unlike GSTR-1 which contains invoice-level details, GSTR-3B summarizes your total outward supplies, inward supplies liable to reverse charge, ITC claimed, and tax payable.

GSTR-3B is the return where you actually pay your GST liability to the government.

GSTR-3B Due Dates for 2025

Tables in GSTR-3B

Table 3.1 – Outward Supplies

Report total taxable value and tax for outward supplies including:

• Taxable supplies (other than zero-rated and reverse charge)
• Zero-rated supplies (exports and SEZ)
• Nil-rated, exempted, and non-GST supplies
• Inward supplies on which reverse charge is payable

Table 3.2 – Inter-State Supplies to Unregistered Persons

State-wise breakup of inter-state B2C supplies and supplies to composition dealers.

Table 4 – Input Tax Credit

Claim ITC based on GSTR-2B data. This section includes:

• 4(A) – ITC available (import, inward supplies, ISD credit)
• 4(B) – ITC reversed (as per rules 42 and 43, blocked credits)
• 4(C) – Net ITC available
• 4(D) – Ineligible ITC

Table 5 – Interest and Late Fee

System auto-computes interest on late payment and late filing fees.

Table 6 – Tax Payment

Summary of tax payable vs. ITC utilized, with remaining liability payable in cash via electronic cash ledger.

Step-by-Step GSTR-3B Filing

1. Login to GST Portal and navigate to Returns → GSTR-3B
2. Select the return period for which you want to file
3. Fill Table 3.1 with outward supply details (auto-populated from GSTR-1)
4. Fill Table 3.2 for inter-state unregistered supplies
5. Verify Table 4 for ITC (auto-populated from GSTR-2B — verify and adjust)
6. Review tax computation in Table 6
7. Offset liability using ITC from electronic credit ledger
8. Pay remaining tax through challan in electronic cash ledger
9. Submit and file using DSC or EVC

Common Mistakes in GSTR-3B Filing

• Mismatch with GSTR-1 – Ensure outward supply values match between GSTR-1 and GSTR-3B
• Claiming excess ITC – ITC in GSTR-3B cannot exceed GSTR-2B by more than a certain threshold
• Ignoring reverse charge – Forgetting to report inward supplies under RCM
• Wrong tax head offset – IGST credit must be used in the correct order (IGST first, then CGST/SGST)

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FileWithUs.ai automatically prepares your GSTR-3B summary from your invoicing data. With real-time ITC tracking and automated tax calculations, you can review and file in minutes instead of hours. The platform alerts you before due dates so you never incur late fees.