GST Tip of the Day: Pay Your Suppliers Within 180 Days or Reverse the ITC

Most small businesses focus on claiming input tax credit (ITC) but forget there is a condition attached to keeping it: you must actually pay your supplier. Under the second proviso to Section 16(2) of the CGST Act (read with Rule 37), if you do not pay your supplier the invoice value plus tax within 180 days from the date of the invoice, the ITC you claimed has to be reversed.

This catches a lot of businesses off guard, especially those running on extended credit terms with vendors.

What the rule actually says

• You can claim ITC on a purchase invoice in the normal course.
• But if the payment (value of supply + the GST on it) is not made to the supplier within 180 days of the invoice date, you must reverse that ITC.
• The reversal is done in your GSTR-3B, and interest applies on the reversed amount.
• The good news: once you eventually make the payment, you are allowed to re-claim that ITC. The credit is not lost forever, only deferred.

Why this matters for cash-strapped businesses

It is common to receive goods or services, claim the credit, and then stretch the supplier payment over several months. That's fine commercially, but from a GST standpoint the clock is ticking. If a 180-day-old invoice is still unpaid and you've already taken the credit, you are technically holding ITC you are not entitled to right now.

During an audit or scrutiny, mismatched or unsupported ITC is one of the first things officers look at. An ageing payables list with old unpaid invoices is an easy red flag.

What to do today

1. Pull an ageing report of your accounts payable. Most accounting software can generate one in a couple of clicks.
2. Flag every purchase invoice older than 150 days that is still unpaid. Give yourself a buffer before the 180-day mark.
3. Cross-check against ITC already claimed. If you took credit on those invoices, you have a decision to make: pay the supplier, or reverse the ITC.
4. Reverse where needed in your next GSTR-3B, along with applicable interest, rather than waiting for a notice.

A few practical points

• The 180 days runs from the invoice date, not the date you booked the purchase or received the goods.
• Partial payments matter — if only part of an invoice is paid, the reversal applies proportionately to the unpaid portion.
• Certain supplies, such as those on which tax is payable under reverse charge, work differently since you are paying the tax directly. Don't apply this rule mechanically to RCM transactions.
• Keep proof of payment (bank statements, UTR numbers) linked to invoices. When you re-claim reversed ITC after paying, you'll want a clean trail.

The takeaway

ITC is not a one-time event at the point of claiming — it carries an ongoing condition that you settle your supplier's dues. Build a simple monthly habit: review payables ageing, isolate anything nearing 180 days, and either pay or reverse before filing GSTR-3B. It takes a few minutes and saves you interest, notices, and uncomfortable questions later.

A reconciled payables ledger is just as important to your GST hygiene as a reconciled GSTR-2B. Treat them as two sides of the same compliance coin.