The Invoice That Sat Unpaid for Six Months: A 180-Day ITC Lesson

A purchase, a credit, and a forgotten payment

Ravi runs a small furniture manufacturing unit in Jaipur. In April, he bought timber and fittings worth ₹10,00,000 plus ₹1,80,000 GST (18%) from a regular supplier. He uploaded the invoice, it showed up in his GSTR-2B, and he happily claimed the full ₹1,80,000 as input tax credit (ITC) in his April GSTR-3B.

So far, so normal. The credit reduced his tax outgo, cash flow felt comfortable, and Ravi moved on.

The problem? He never actually paid the supplier. A festive-season cash crunch, a few delayed customer payments, and the bill simply sat there. By the time his accountant flagged it in November, the invoice was more than 180 days old — and still unpaid.

What the law actually says

Under the second proviso to Section 16(2) of the CGST Act, if you claim ITC on an invoice but do not pay the supplier (the value of supply plus tax) within 180 days of the invoice date, you must reverse that ITC.

It's a rule many businesses forget because the credit feels "earned" the moment it appears in GSTR-2B. But GST law treats ITC as conditional — you only truly keep it once the supplier is paid.

The reversal isn't permanent. Once you eventually pay, you can re-claim the credit with no time limit attached to that re-availment. But the reversal — and the interest — in the meantime are very real.

Working out Ravi's numbers

Here's what Ravi faced:

• ITC originally claimed: ₹1,80,000
• Status at 180 days: supplier unpaid
• Action required: reverse ₹1,80,000 and add it back to output tax liability
• Interest: payable on the reversed amount for the period the credit was wrongly retained

Assuming roughly ₹1,80,000 reversed and interest at 18% per annum for about two months until he corrected it, the interest worked out to roughly:

₹1,80,000 × 18% × (60/365) ≈ ₹5,326

So a forgotten payment cost Ravi a temporary ₹1.8 lakh dent in his credit ledger plus around ₹5,300 of pure interest — money he never had to lose.

How he fixed it

Ravi did three things:

1. Reversed the ₹1,80,000 ITC in his next GSTR-3B and paid the associated interest.
2. Cleared the supplier's bill in full — value plus tax.
3. Re-claimed the ₹1,80,000 in the GSTR-3B for the month he made the payment.

Net result: he got his credit back, but the interest was gone for good. An avoidable leak.

The takeaways for your business

• ITC is conditional, not automatic. Appearing in GSTR-2B is not the finish line — paying your supplier is.
• Track invoice ageing. Run a simple report each month of purchase invoices crossing, say, 150 days unpaid, so none slip past 180.
• Reverse proactively. If you can't pay in time, reverse the credit yourself before a notice forces you to — you'll save on higher interest and scrutiny.
• Re-claim freely once paid. The good news: re-availment after payment isn't blocked by the usual time limit, so you don't lose the credit forever.

For a small manufacturer like Ravi, cash flow will always be lumpy. But the 180-day clock doesn't care about your festive-season crunch. Build the check into your monthly close, and a ₹5,000 interest surprise becomes a non-event.