Letter to Supplier for GST Mismatch: 4 Word Templates

In our practice reconciling monthly purchase registers against auto-populated GSTR-2B statements, we regularly find vendor reporting mistakes. When a vendor omits an invoice or types the wrong state code, calling accounts staff rarely fixes the error in time. A written letter gives the supplier clear invoice numbers, dates, tax amounts, and the exact portal correction needed.

For the complete workflow of matching purchase registers with portal statements, read our GSTR-2B reconciliation and ITC matching guide.

Why written communication is essential under current GST rules

Statutory restrictions make vendor compliance a legal condition for your credit eligibility. Under Section 16(2)(aa) of the CGST Act, Input Tax Credit can only be claimed if the supplier furnishes invoice details in Form GSTR-1 or through the Invoice Furnishing Facility (IFF) and those details appear in Form GSTR-2B. Under Rule 36(4) of the CGST Rules, no provisional ITC buffer is available.

If you claim credit missing from GSTR-2B, the GST system generates an automated notice in Part A of Form GST DRC-01C under Rule 88D of the CGST Rules. You have seven days to either pay back the excess tax with interest under Section 50 or file an explanation. Issuing a formal communication to your vendor safeguards your working capital and creates documentary evidence for internal audit.

Common mistake: Waiting until the annual return or annual audit to notify suppliers. Under Section 16(4), the statutory deadline to claim ITC for any financial year is 30 November following the end of that financial year or the date of filing the annual return, whichever is earlier. Delayed supplier follow-ups often lead to permanently lost tax credits.

Missing invoice in GSTR-2B

Use this format when your accounting books show purchases and payments, but the vendor failed to declare the invoice in their monthly Form GSTR-1 or quarterly IFF.

To, The Accounts Department, Shree Balaji Traders, 22 Industrial Estate, Surat, GSTIN: 24AAACB1234D1ZP Date: 24/10/2026 Subject: Request to upload missing tax invoices in GSTR-1 or GSTR-1A for ITC availment Dear Sir or Madam, During our monthly GST reconciliation for September 2026, we observed that the following tax invoices issued by you are missing from our auto-populated Form GSTR-2B: Invoice Number: INV-2026-088, Date: 12/09/2026, Taxable Value: Rs 1,00,000, CGST: Rs 9,000, SGST: Rs 9,000, Total: Rs 1,18,000. Invoice Number: INV-2026-094, Date: 20/09/2026, Taxable Value: Rs 50,000, CGST: Rs 4,500, SGST: Rs 4,500, Total: Rs 59,000. Total Unreflected Tax Credit: Rs 27,000. As per Section 16(2)(aa) of the CGST Act, we cannot claim Input Tax Credit on these invoices until you declare them in your Form GSTR-1 or add them via Form GSTR-1A. Please upload these invoices in your upcoming return filing so that the credit reflects in our GSTR-2B statement. Kindly share the filing ARN once completed for our records. Yours faithfully, Apex Engineering Works Accounts Department

Wrong GSTIN reported by supplier

Suppliers occasionally upload B2B invoices against an incorrect GSTIN or mark an invoice as B2C. When this occurs, the credit never reaches your GST portal dashboard.

To, The Accounts Department, Shree Balaji Traders, GSTIN: 24AAACB1234D1ZP Date: 24/10/2026 Subject: Notice of invoice uploaded against incorrect GSTIN in Form GSTR-1 Dear Sir or Madam, On verifying our auto-populated Form GSTR-2B for September 2026, we noted that the tax credit for Invoice Number INV-2026-105 dated 15/09/2026 with taxable value Rs 2,00,000 and GST Rs 36,000 has not been credited to our account. Our review shows that this invoice was declared against an incorrect GSTIN or uploaded as a B2C supply in your Form GSTR-1. Please amend the recipient GSTIN to our registered number 27AAAAA0000A1Z5 in Table 9A of your Form GSTR-1 or via Form GSTR-1A. Until this correction is completed on the GST portal, the tax credit remains blocked for our unit. Please confirm once the amendment is filed. Yours faithfully, Apex Engineering Works Accounts Department

Incorrect tax head declared

When an interstate supplier charges or reports CGST and SGST instead of IGST, or sets an incorrect Place of Supply, your business cannot utilize the credit correctly in Form GSTR-3B.

To, The Accounts Team, Shree Balaji Traders, GSTIN: 24AAACB1234D1ZP Date: 24/10/2026 Subject: Discrepancy in tax head for Invoice INV-2026-112 Dear Accounts Team, This is regarding Invoice Number INV-2026-112 dated 18/09/2026 for the supply of machinery spares amounting to Rs 1,18,000. In your Form GSTR-1 filing, this transaction was reported under CGST Rs 9,000 and SGST Rs 9,000 with Place of Supply recorded as Gujarat (State Code 24). Because this is an interstate supply delivered to our factory in Maharashtra (State Code 27), the tax should be reported as IGST Rs 18,000. Due to this reporting discrepancy, our auto-populated Form GSTR-2B reflects misclassified credit that we cannot offset against our output tax liability. Kindly file an amendment in Table 9A of Form GSTR-1 to rectify the Place of Supply and tax head for this invoice. Please share the amendment ARN once filed. Yours sincerely, Apex Engineering Works Taxation Team

Payment hold notice for persistent GST mismatch

If informal reminders fail, commercial terms justify withholding payment of the GST component or the pending bill until the vendor uploads the invoice.

To, The Finance Controller, Shree Balaji Traders, GSTIN: 24AAACB1234D1ZP Date: 24/10/2026 Subject: Notice of payment hold on Invoice INV-2026-088 due to non-reflection in GSTR-2B Dear Sir or Madam, We refer to our earlier communications dated 05/10/2026 and 15/10/2026 regarding the missing tax credit for Invoice Number INV-2026-088 dated 12/09/2026 having a GST component of Rs 18,000. This invoice still does not appear in our GSTR-2B statement. Under Section 16(2)(aa) of the CGST Act, we cannot claim Input Tax Credit on unreflected invoices. In addition, Rule 88D mandates tax demand intimations in Form GST DRC-01C for discrepancies between GSTR-3B and GSTR-2B. Consequently, we have withheld payment of Rs 18,000 against your pending bill until you furnish this invoice in your GSTR-1 return and provide proof of submission. Please file the missing invoice on the GST portal immediately. Upon receipt of valid GSTR-2B reflection, the withheld amount will be cleared in our next payment cycle. Yours faithfully, Apex Engineering Works Finance Department

Worked example: financial impact of vendor delay

Consider a manufacturing firm, Modern Gears Ltd, purchasing industrial parts from Vendor Alpha during September 2026.

Invoice	Purchase register	Status in GSTR-2B	Tax impact
INV-101	₹1,18,000 (Tax ₹18,000)	Reflected	Eligible ITC ₹18,000
INV-102	₹2,36,000 (Tax ₹36,000)	Missing	Blocked ITC ₹36,000

Modern Gears Ltd paid the entire invoice amount of ₹2,36,000 to Vendor Alpha. However, because Vendor Alpha omitted INV-102 from GSTR-1, Modern Gears Ltd could not take credit for ₹36,000 in September 2026. They had to discharge ₹36,000 in cash through their Electronic Cash Ledger to file GSTR-3B.

Formula for working capital cash loss:

Cash loss = Unclaimed ITC on omitted invoices = ₹36,000.

Issuing the missing invoice notice prompted Vendor Alpha to amend their filing via Form GSTR-1A before filing GSTR-3B, ensuring Modern Gears Ltd obtained credit in the subsequent tax run.

Frequently asked questions

Why must a buyer send a letter to supplier for GST mismatch?

Under Section 16(2)(aa) of the CGST Act, a buyer cannot claim Input Tax Credit unless the supplier reports the invoice in GSTR-1 or IFF and it appears in the buyer's GSTR-2B. A formal letter establishes a written audit trail and prompts the vendor to upload or rectify the invoice before return deadlines.

Can a supplier correct a GST mismatch before filing GSTR-3B?

Yes, using Form GSTR-1A. A supplier can add omitted invoices or amend details declared in their filed GSTR-1 for the current period before submitting Form GSTR-3B.

What statutory risk does the buyer face if the mismatch is ignored?

If a buyer avails ITC that is missing from GSTR-2B and exceeds statutory thresholds, the GST portal issues an intimation in Form GST DRC-01C under Rule 88D, allowing 7 days to pay back the excess credit with interest under Section 50 or submit an explanation.

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Last checked: 24 October 2026. Sources: CBIC Section 16 CGST Act, GSTN Rule 88D DRC-01C Advisory.