Your Credit Depends on Someone Else’s Filing
GSTR-2B is an auto-generated statement of the input tax credit available to you for a period, built from what your suppliers have reported. Your purchase register is what you actually bought. The gap between them is the single most consequential reconciliation in GST, because credit follows GSTR-2B rather than your invoice file, and because Rule 88D automates a comparison between the credit you claim in GSTR-3B and what GSTR-2B supports, generating Form DRC-01C where the difference exceeds the notified threshold.
The three buckets
Every reconciliation produces exactly three categories.
1. Matched. In GSTR-2B and in your purchase register, with the same value and tax. Nothing to do.
2. In your books, not in GSTR-2B. The supplier has not filed, has filed late, has reported the invoice against the wrong GSTIN, or has reported a different value. Credit generally waits.
3. In GSTR-2B, not in your books. An invoice you have not recorded, an invoice raised to you that you were not expecting, or a supplier error attributing someone else’s supply to your GSTIN. Investigate before claiming.
Bucket 2 is where the money sits
The most common cause is a supplier filing after the cut-off, which pushes the credit into a later month’s GSTR-2B rather than losing it.
Three sub-cases worth separating:
Timing. The supplier filed late. The credit arrives next period. Track it rather than chasing it.
Wrong GSTIN. The supplier reported your invoice against another registration of yours, or against someone else entirely. Only the supplier can fix this.
Not filed at all. The supplier has not filed the return. Your credit does not exist until they do, and there is an annual cut-off beyond which it is lost.
This is why supplier follow-up is a monthly process rather than a year-end exercise, and why a contractual obligation on suppliers to file correctly is worth having. See our article on GST in contracts.
The differences that are not errors
Some gaps are structural and will never close. Identify them once and document them, because they otherwise reappear in every reconciliation and in every notice.
Import IGST. Paid at the port, not routed through a supplier’s GSTR-1, so it does not appear in GSTR-2B. For an importer the difference is permanent and explainable.
Reverse charge. Liability discharged in cash, with credit taken, but no supplier invoice flowing through GSTR-2B in the ordinary way.
ISD credit, where applicable.
A business that cannot explain its own structural differences will pay a DRC-01C it did not owe.
The process
Download GSTR-2B after it is generated for the period
Match against the purchase register on GSTIN, invoice number, date, taxable value and tax
Classify into the three buckets
Separate structural differences from genuine gaps
Apply the eligibility filters: Section 16 conditions, Section 17(5) blocked categories, and the payment-overdue reversal
Decide the claim for the period
Document it, because this working paper answers a DRC-01C
What Rule 88D does
Where the credit claimed in GSTR-3B exceeds what GSTR-2B supports beyond the notified threshold, Form DRC-01C is generated automatically. You either pay the difference with interest or explain it.
Where the gap is import IGST or a timing difference, the answer is an explanation, not a payment. That distinction is worth real money and most businesses do not make it.
What is coming
Sources report that from the July 2026 tax period the eligible credit figure in Table 4A of GSTR-3B is itself to be auto-populated and non-editable, with corrections routed through the Invoice Management System before GSTR-2B is generated.
If that holds, the reconciliation moves earlier still: the decisions have to be made before GSTR-2B is generated rather than before GSTR-3B is filed. Verify the position and the date before planning around it, but plan for it.
How Northrop LLP helps
Northrop LLP runs the monthly GSTR-2B reconciliation, documents the structural differences so they are explained in advance, chases supplier gaps, and answers DRC-01C intimations where the difference is not a shortfall.