Every CA firm has its own ITC reconciliation ritual. Some teams pull 2A every week. Some swear by 2B and ignore 2A entirely. Some compare both against books and argue with the client about which one is right. There's no universal answer, but there is a defensible order — and once you internalise it, ITC season gets a lot quieter.
What each one actually is
GSTR-2A — the live feed
2A is a dynamic statement. It updates every time a supplier files their GSTR-1, regardless of when. If your supplier files a 2025-26 invoice late in 2026-27, it shows up in your 2A retroactively. Useful for monitoring, dangerous for ITC claims — because what's there today might not be there next week.
GSTR-2B — the frozen snapshot
2B is generated on the 14th of every month and contains all invoices reported by your suppliers between the 12th of the previous month and the 11th of the current month. Once generated, it's frozen. Under Rule 36(4), this is what determines your ITC eligibility for that period.
Your purchase books
Whatever your client has booked. This includes invoices the supplier hasn't yet filed, provisional entries, and the occasional missed bill from three months ago that the bookkeeper just got around to entering.
The priority order we follow
For any given month's ITC claim, work in this order:
- Start with 2B. This is your defensible baseline. Whatever's in 2B, you can claim — full stop. The GST portal has frozen it; it's not going anywhere.
- Reconcile 2B against your purchase books. Anything in books but missing from 2B falls into one of three buckets: supplier hasn't filed yet (wait), supplier filed late and it'll appear in next month's 2B (claim next month), or supplier never filed (chase them).
- Use 2A as your "what's coming" signal. If 2A shows invoices that aren't yet in 2B (because the supplier filed after the 11th), you know they'll land in next month's 2B. Don't claim them now, but flag them for the next period.
- Books-only entries are at-risk ITC. If it's in your books but in neither 2A nor 2B, you have a missing supplier filing. Issue a follow-up email immediately — don't wait until year-end when everyone has forgotten the transaction.
The tolerance question
Most firms allow some small mismatch tolerance — say, ₹100 or 0.5% — before flagging a discrepancy. The thinking is that rounding differences between supplier and buyer are inevitable. We don't disagree, but be explicit: configure your tolerance at the firm level and apply it consistently. Mismatches caught above tolerance go into the "ask the supplier" pile. Below tolerance, you absorb the difference.
What automation actually solves
The boring part of reconciliation isn't the comparison — it's the data aggregation. Pulling 2A from the portal (which times out), exporting 2B, exporting books, lining them up, doing the VLOOKUP, finding the mismatches.
Once that's automated, reconciliation becomes a 15-minute review session instead of a four-hour data wrangle. The judgment calls (chase this supplier, write off this rounding difference, claim this provisional ITC) remain yours. The grunt work doesn't have to be.
Reconciliation is not about finding mismatches. It's about deciding what to do with them. The first part should be automatic. The second is what you're paid for.
