Input tax credit (ITC) can only be claimed for invoices your suppliers have reported. Every month, the purchase register in your books must be matched with GSTR-2B from the GST portal. Here is a reliable Excel method.

1. Get the two lists

• GSTR-2B: download the Excel file from the GST portal (Returns → GSTR-2B → Download). Use the B2B sheet.
• Books: export the purchase register from Tally/Busy with supplier GSTIN, invoice number, date, taxable value and tax amounts.

Put them on sheets named 2B and Books, each formatted as a Table (Ctrl+T).

2. Clean the matching fields

Invoice numbers are written differently by suppliers and accountants: “INV/21-22/045”, “inv-21-22-45”, “045”. Build a cleaned version in both tables:

“`excel
=UPPER(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(TRIM([@[Invoice No]]),”/”,””),”-“,””),” “,””),”\”,””))
“`

Also =UPPER(TRIM([@GSTIN])) for GSTINs.

3. Build a match key

“`excel
=[@[GSTIN Clean]] & “|” & [@[Invoice Clean]]
“`

4. Match both ways

In Books:

“`excel
=IF(COUNTIF(Tbl2B[Key], [@Key]), “In 2B”, “Missing in 2B”)
“`

In 2B:

“`excel
=IF(COUNTIF(TblBooks[Key], [@Key]), “In books”, “Not in books”)
“`

5. Compare amounts for matched invoices

“`excel
=IFERROR([@[Total Tax]] – INDEX(Tbl2B[Total Tax], MATCH([@Key], Tbl2B[Key], 0)), “”)
“`

Flag differences above ₹1 (rounding) with conditional formatting.

6. Read the result

7. Vendor follow-up list

“`excel
=FILTER(TblBooks[[Supplier]:[Total Tax]], TblBooks[Status]=”Missing in 2B”, “All matched”)
“`

(Excel 365). In older Excel, filter the Status column and copy. A pivot by supplier shows who owes you the most ITC.