The matching itself is not difficult. What eats the time is the state of the two files. This post goes in the order you would work: prepare both files, line up the columns, match in passes, and deal with pairs that are almost right. A six-invoice example at the end can be reproduced on a blank sheet.
This page is one part of our GSTR-2B reconciliation guide, which shows how the whole process fits together.
Step 1: get both files into the right shape
The GSTR-2B side
Use the Excel download from the portal and do not rename or reformat its columns. The file holds the B2B, B2BA, CDNR and CDNRA tables. Invoice matching starts with B2B; the other sheets carry amendments and credit or debit notes and are handled separately. The portal steps are in how to download GSTR-2B from the GST portal, and the meaning of each column is in the GSTR-2B Excel guide.
Download it after the 14th, when GSTR-2B is generated.
The purchase side: register, book and ledger
People use three words for nearly the same thing, and only one of them is fit for this job. A purchase register, also called the purchase book, lists each purchase voucher with its date, supplier, supplier GSTIN, supplier’s invoice number, taxable value and tax heads. That is what you need. A purchase ledger or a supplier’s ledger account is an account statement: postings and a running balance, often a single total per voucher with no GSTIN and no tax split. It shows what you owe, not what credit you can claim.
If you only have a ledger, ask your accounting software for its GST purchase register report rather than rebuilding one from ledger lines. Guides for exporting a clean register are ready for Tally Prime, Busy, Marg and Zoho Books.
Step 2: the columns that must line up
| Field | Take it from | Why it has to line up |
|---|---|---|
| Supplier GSTIN | The GSTIN field of the supplier, not the party name | First half of the key. Trim spaces, use capitals. |
| Invoice number | The supplier’s bill number, not your own voucher number | Second half of the key. Many exports carry both; matching on your voucher number fails almost every row. |
| Invoice date | The date on the supplier’s invoice, not the date you posted it | Not needed to find a match, but essential for pairing leftovers in pass 3. |
| Taxable value | Register | Sanity check: tax divided by taxable value should give a sensible rate. |
| IGST, CGST, SGST, cess | Separate columns | Compare the total, then look at heads. A difference in heads with the same total means a place of supply or booking error. |
| Invoice value | Register | For reference only. Do not match on it. |
A note on the invoice number column. Rule 46(b) limits an invoice number to sixteen characters made of letters, numerals, hyphen and slash. If your register shows a space, a hash or more than sixteen characters, go back to the invoice copy before you trust that row.
Step 3: clean the data without overwriting it
Never edit the exported columns. Add helper columns beside them so you can always see what the supplier and your staff actually typed.
- Format the invoice number column as text before pasting. Otherwise Excel turns 000456 into 456 and you lose the original.
- Clean the GSTIN: trim spaces, convert to capitals.
- Build two keys: Key A is GSTIN and the invoice number exactly as typed. Key B is GSTIN and the invoice number in capitals, with spaces, hyphens, slashes and hashes removed and any zeros at the very start of the number dropped.
- Check that dates are real dates. A date stored as text such as “03-08-2026” sorts and compares wrongly.
- Flag duplicates on Key B. A second row for the same supplier and invoice must not be matched again; leave it out of the ITC total.
- Tag, do not delete, rows that will never appear against a supplier’s filing, such as reverse charge entries (see RCM in GSTR-2B).
Step 4: match in four passes
Pass 1, exact key. Look up Key A of each register row in the GSTR-2B sheet. Everything found is paired. Mark both sides matched so the pool shrinks with each pass.
Pass 2, cleaned key. Run Key B on what is left. This is where slash-versus-hyphen and leading zeros are settled. Our guide to invoice number mismatches lists the patterns. Keep it strict: the more you strip, the likelier you join two different invoices.
After each key match, check the tax. Add IGST, CGST, SGST and cess on both sides and take the difference. Anything up to a rupee is normal rounding, since Section 170 rounds to the nearest rupee while suppliers’ software rounds in its own way; the round-off guide covers the accounting. Anything larger is a partial match, handled in step 5.
Pass 3, candidate pairs. For the rows still unmatched on both sides, look for the same GSTIN, the same total tax to the rupee, and dates within a few days of each other. Where exactly one candidate exists on each side, you have a probable pair. It is only a candidate. Confirm it against the invoice copy, then correct whichever side is wrong. If your entry is wrong, fix the books; if the supplier reported it wrongly, the supplier has to amend. GSTR-1A lets a supplier amend or add current-period details after filing GSTR-1 and before GSTR-3B.
Pass 4, supplier totals. For GSTINs that still have leftovers, compare the register total and the GSTR-2B total. What remains is genuinely missing on one side.
Step 5: handle partial matches
- Number matches, tax differs. Get the invoice copy. Either the supplier reported a different figure or your entry is wrong. Until GSTR-2B carries the figure you believe is correct, the safe credit is the GSTR-2B figure, because ITC turns on what the supplier furnished and GSTR-2B communicated under Section 16(2)(aa).
- The same invoice appears on several GSTR-2B rows. Add those rows up before comparing with the single register row.
- One bill in your books, two in the supplier’s filing, or the other way round. Compare the group total for that GSTIN and date instead of forcing a one-to-one pair.
- Same total tax, different heads. For example, IGST in your books and CGST plus SGST in GSTR-2B. Flag it for correction before you claim.
- Matched is not the same as claimable. Pairing a row only proves it is in GSTR-2B. Receipt of the goods, payment within 180 days and the time limit are separate tests, and the availability details in the sheet itself (the columns are listed in the Excel guide) should be read before you claim.
Worked example with six invoices
A distributor has six purchases in a month. Figures are tax only, in rupees.
| Supplier | Books no. | Books tax | 2B no. | 2B tax | Matched at | Outcome |
|---|---|---|---|---|---|---|
| Bharat Fasteners | BF/0231 | ₹9,000 | BF/0231 | ₹9,000 | Pass 1 | Matched |
| Kaveri Packaging | KP-118 | ₹4,500 | KP/118 | ₹4,500 | Pass 2 | Matched |
| Om Sai Traders | 000456 | ₹13,500 | 456 | ₹13,500 | Pass 2 | Matched |
| Deccan Tools | DT/22/090 | ₹6,300 | DT/22/090 | ₹6,120 | Pass 1 | Tax differs by ₹180 |
| Sagar Chemicals | SC/26/0774 | ₹22,500 | SC/26/774 | ₹22,500 | Pass 3 | Matched after checking the invoice copy |
| Ratan Electricals | RE/1108 | ₹11,700 | Nil | Nil | None | Not in GSTR-2B |
Pass 1 caught two rows, and pass 2 caught two more by removing punctuation and the leading zeros. The Sagar Chemicals row escaped both because the zero sits after the slash, not at the start. Pass 3 found it: same GSTIN, same ₹22,500, dates two days apart, one candidate on each side. The invoice copy shows SC/26/0774, so the supplier reported the number without its zero and the register is correct. The ITC of ₹22,500 is in GSTR-2B and available.
Now prove the result with totals.
| Step | Tax |
|---|---|
| Register total (₹9,000 + ₹4,500 + ₹13,500 + ₹6,300 + ₹22,500 + ₹11,700) | ₹67,500 |
| Less: Deccan Tools, tax differs | ₹180 |
| Less: Ratan Electricals, not in GSTR-2B | ₹11,700 |
| Equals GSTR-2B total (₹9,000 + ₹4,500 + ₹13,500 + ₹6,120 + ₹22,500) | ₹55,620 |
₹67,500 − ₹180 − ₹11,700 = ₹55,620, exactly the GSTR-2B total. Nothing is unexplained. Ask Deccan Tools for its invoice copy and, until GSTR-2B shows the higher figure, treat ₹6,120 as the credit; and follow up Ratan Electricals, using the guide for suppliers who have not filed GSTR-1. GSTR-3B for a monthly filer is due on the 20th, so start the chase on the 14th.
Common mistakes
Matching on your voucher number. Registers often carry your internal voucher number beside the supplier’s bill number. Only the second one exists in the supplier’s GSTR-1.
- Matching on invoice value. It includes freight and round-off and moves for reasons unrelated to credit. Match on the key, compare the tax.
- Using the wrong period’s GSTR-2B. An invoice booked in September may be reported by the supplier in a different month. Check the freeze date guide before calling it missing.
- Using “contains” matches to save time. Invoice 12 will match 112, 120 and 1200.
- Only looking from the register outward. Invoices in GSTR-2B that you never booked are invisible to a register-to-2B lookup. Run the reverse direction too, and confirm the goods or services were actually received before booking them.
Frequently asked questions
Which columns are the minimum I need to match invoices with GSTR-2B?
The supplier GSTIN, the supplier's invoice number and the tax amount. The invoice date and taxable value are not needed to find a match, but they help you pair leftovers and spot rate errors.
Should I match on invoice value or on tax?
Find the pair with the GSTIN and invoice number first, then compare tax. Invoice value includes freight, round-off and other charges, so it can differ for reasons that have nothing to do with ITC. Tax is what you claim, so tax is what you compare.
Can I use my purchase ledger instead of the purchase register?
Rarely. A ledger account lists postings and balances, often one line per voucher with no GSTIN or tax split. For invoice-by-invoice matching you need the GST purchase register report from your accounting software, with one row per supplier invoice.
Let the tool do the key matching
The tool matches on the supplier GSTIN plus the cleaned invoice number (capitals, punctuation and leading zeros removed), checks tax within ₹1, and lists the leftovers on both sides so you can do pass 3 by eye. It exports the result as a CSV. Your GSTR-2B and purchase register files are read in your browser and never uploaded to any server.
Related guides
- GSTR-2B reconciliation guide: the complete guide to ITC matching
- how does GSTR-2B reconciliation work: what happens step by step
- GSTR-2B vs purchase register: why the totals differ and how to find the difference
- Invoices in GSTR-2B but not in my books: how to investigate them
- GSTR-2B Table 4D mismatch: unmatched invoices and fixes
- How accountants can automate GSTR-2B reconciliation
- GSTR-2B rejected invoices fix: how to resolve portal errors
- The same invoice appears twice in reconciliation: how do you spot and fix it
Last checked: 30 Sep 2026. Sources: CGST Act, Section 16, CGST Rules, Rule 46, CGST Act, Section 170, GSTN FAQs on comparison of liability declared and ITC claimed, GSTN user guide on viewing e-filed returns, GSTN GSTR-3B user guide, GSTN FAQs on GSTR-1A.