ITC reconciliation: a monthly workflow that actually catches mismatches

Input tax credit is where most GST disputes are born and where most practice hours quietly disappear. The rules changed the game years ago: credit is allowed only to the extent it appears in GSTR-2B, so a supplier who files late or wrong directly shrinks your client's working capital. A reconciliation that runs once a quarter, in a panic, before the annual return will not catch this in time — you need a tight monthly rhythm.

Why monthly, and why GSTR-2B is the anchor

The whole exercise hangs on GSTR-2B, the static, auto-drafted statement generated on the 14th of each month. Unlike the older 2A, it does not keep shifting, which makes it the correct number to reconcile against because it is the figure the system uses to compute eligible credit. Pulling it monthly matters for three reasons:

• Section 16(4) time limits. Credit for an invoice must be claimed by 30 November following the end of the financial year (or the date of the annual return, whichever is earlier). Catch a missing invoice in month three, not in October.
• Cash flow. Every rupee of ineligible or unmatched credit you wrongly claim is a rupee that may be reversed with interest under Section 50.
• Supplier leverage. A vendor is far more likely to fix a return for last month than for something nine months stale.

A quarterly cleanup compresses twelve problems into one weekend. A monthly pass keeps each month's exceptions small enough to actually resolve.

The four-bucket match

Reconciliation is not "do the totals agree." It is a line-level comparison between the purchase register and GSTR-2B, sorting every invoice into one of four buckets:

• Matched — same GSTIN, invoice number, date and tax. Claim and move on.
• In 2B, not in books — usually a missed booking, or an invoice the client never sent you. Book it or query it.
• In books, not in 2B — the supplier has not filed, or filed under the wrong GSTIN/period. This is the dangerous bucket: do not claim, follow up.
• Matched GSTIN/invoice but value or tax differs — typos, rounding, or a credit note one side has not recorded.

The friction is almost always in the third bucket. Build a standing supplier follow-up list keyed to GSTIN, so the same defaulting vendors surface every month and the client can decide whether to withhold payment until the credit appears.

Handling the messy edges

Real registers are never clean. A workflow that survives contact with actual data needs rules for the edges:

• Tolerance limits. Set a paise/rupee threshold (say up to 2 rupees of tax difference) to auto-pass, so you are not chasing rounding.
• Invoice number normalisation. Strip leading zeros, slashes and spaces before matching — most "mismatches" are formatting, not substance.
• Provisional vs final. Tag credit you are holding back because the supplier has not filed, and carry that tag forward until it clears.
• Credit notes and reverse-charge. Reconcile these separately; they distort a straight invoice-to-invoice match.
• Cross-period invoices. A March invoice appearing in April's 2B is normal — match on document, not on the month it landed.

Document the decision on every exception. When a notice arrives eighteen months later, the reconciliation working that shows why a credit was held or claimed is your strongest defence.

Reconcile against GSTR-2B every month at line level — the credit you cannot trace is the credit you should not claim.

Closing the loop into the return

Reconciliation is wasted if it does not flow into GSTR-3B. The monthly close should produce a single eligible-credit figure, the list of provisional credits parked for later, and the follow-up actions assigned with owners and dates. Keep a running carry-forward sheet so that credit held in one month and released in the next is never double-claimed or quietly lost. Tie the final 3B credit number back to the reconciliation working so any reviewer can trace it end to end.

How Bizotic One helps

Bizotic One keeps each client's GST filing status, purchase data and follow-up tasks in one workspace, so the monthly 2B reconciliation, the supplier chase-ups and the 3B figure stay connected instead of scattered across spreadsheets and inboxes. Assign exceptions as tasks, track which suppliers keep defaulting, and carry the working into the next month — without re-keying it anywhere.