Input tax credit is the heart of GST — and the most contested line item in assessments. Claim too little and you burn cash; claim too much or too early and you invite a notice. Here is how to claim the maximum ITC you are legally entitled to, and nothing more.

The four conditions of Section 16

ITC is only available when all four are true:

  1. You possess a valid tax invoice or debit note.
  2. You have actually received the goods or services.
  3. The supplier has paid the tax to the government — evidenced by the invoice appearing in your GSTR-2B.
  4. You have filed your own GSTR-3B.

Since Rule 36(4) became fully effective, ITC claimed in excess of GSTR-2B is treated as ineligible — the “provisional 5%” cushion no longer exists.

Match GSTR-2B every single month

GSTR-2B is a static, monthly snapshot — unlike the dynamic 2A. Build this habit:

  • Download 2B on the 14th when it generates.
  • Match each purchase ledger entry against it; flag invoices your suppliers have not filed.
  • Follow up with non-filing suppliers in writing — your credit depends on their compliance.

Your purchase register reconciled to GSTR-2B is the single best defense against a mismatch notice under Rule 88C.

Know the blocked credits

Section 17(5) permanently blocks ITC on, among others: most motor vehicles, food and catering, personal consumption, goods lost or written off, and works-contract services for immovable property (unless it is your business input). Claiming these is a guaranteed demand.

The 180-day payment rule

If you do not pay your supplier within 180 days of the invoice date, the ITC you claimed on it must be reversed with interest. Track invoice ageing — this rule catches even well-run businesses at year-end.

A monthly ITC checklist

  • Reconcile purchase register to GSTR-2B before filing 3B.
  • Reverse credit for any invoice unpaid beyond 180 days.
  • Strip out 17(5) blocked credits at entry time, not filing time.
  • Keep debit/credit notes linked to their source invoices.

Muneem’s Smart Purchases module does the 2B matching for you — upload the portal JSON and every purchase bill gets a reconciliation status automatically, with ineligible-ITC reasons tracked per line item.