How to reconcile GSTR-2B with the purchase register

Why this reconciliation matters

Your input tax credit in GSTR-3B is limited to what appears in GSTR-2B. Your books, however, are based on the bills you physically received. The two never agree exactly, because suppliers file late, type wrong numbers, or forget to report. Without a monthly match you either leave credit unclaimed or claim credit that is later questioned. The background is in GSTR-2B and ITC matching.

What you need

• GSTR-2B for the month, downloaded from the portal in Excel.
• Your purchase register for the same month from your accounting software, with supplier GSTIN, bill number, bill date, taxable value, IGST, CGST, SGST and cess. Include expense bills with GST and debit notes from suppliers.
• A list of bills from earlier months that were not yet in GSTR-2B (your pending list).

Step-by-step method

1. Clean the keys. Bill numbers are typed differently: "INV/245", "INV-245", "245". Remove spaces, slashes, dashes and leading zeros in a helper column on both sides. Make GSTINs upper case.
2. Match on GSTIN plus cleaned bill number. This is the main key.
3. Compare amounts for matched pairs: taxable value and each tax head. Allow a small tolerance, say ₹1 to ₹10, for rounding.
4. Try a second pass for unmatched items on GSTIN plus amount, to catch bill number typos.
5. Classify every leftover line using the table below.
6. Act: claim, hold, follow up, or reject in IMS.
7. Update the pending list and carry it to next month.

Types of mismatch and what to do

Worked example: one month

A Kolkata FMCG distributor reconciles November. Purchase register: 58 bills, ITC ₹3,12,400. GSTR-2B: 55 bills, ITC ₹3,06,900.

• 51 bills match exactly: ₹2,88,000.
• 2 bills match on GSTIN and amount but bill number differs by a typo in books: ₹9,500. Fix the books; credit is fine.
• 3 bills in books not in 2B, ₹14,900: the supplier files quarterly and will report them in the quarter's GSTR-1. Hold, add to pending list.
• 2 bills in 2B not in books, ₹9,400: one bill was in transit and arrives on 3 December; one is a supplier's credit note reducing ITC by ₹1,200 that the accountant had not entered.

Claimable now: the 53 matched bills (₹2,97,500), minus the ₹1,200 credit note = ₹2,96,300. The bill for goods arriving in December is claimed in December, when the goods are received. The ₹14,900 waits on the pending list.

Keeping the pending list under control

The pending list is where credit quietly gets lost. Keep it as a simple sheet with supplier name, GSTIN, bill number, bill date, ITC amount, the month you booked it and the date you last followed up. Each month, tick off bills that have now appeared in GSTR-2B and claim them. Anything older than three months deserves a phone call to the supplier, not another email.

Remember the yearly cut-off: credit for a financial year must be claimed by the earlier of 30 November of the next year and the date you file the annual return. In October and November, sort the pending list by bill date and push hardest on bills from the previous year, because after the cut-off that credit cannot be claimed at all.

Tips that save time every month

• Insist on the correct GSTIN on every purchase order, so suppliers bill the right branch.
• Enter the supplier's bill number exactly as printed, not your own inward number.
• Look at IMS weekly, not only at month end.
• Rank pending bills by amount and chase the top five suppliers first.
• Link supplier payments to reporting: many businesses hold the GST portion of a payment until the bill appears in GSTR-2B.

This is general information, not tax advice.

Where Cashflow OS fits

The purchase side of the match comes from your books. Cashflow OS lets you see TallyPrime purchase vouchers, supplier ledgers and bill-wise payables on the phone or web, and export reports to Excel, which is a convenient starting point for the matching sheet. GSTR-2B is downloaded from the GST portal; Cashflow OS does not pull it or file returns.