The Challan Serial Number is a unique 5-digit number (occasionally 6 or 7 digits depending on the bank) assigned by a bank branch to a specific tax payment on a given day. It is a critical component of the Challan Identification Number (CIN) required to verify your tax payment in your Income Tax Return (ITR). [1, 2, 3, 4]

• Definition: It is a running serial number generated by the bank for every transaction processed on a particular date.
• Purpose: It distinguishes your payment from other payments made at the same bank branch on the same day.
• Format: Usually 5 digits, it is often found alongside the 7-digit BSR code and the date of deposit.

You can find this number through several official channels after completing your tax payment:

• Challan Receipt/Counterfoil: It is printed on the physical or digital receipt issued by the bank. Look for a field labeled “Challan Serial No.” or “Serial No.”.
• Income Tax e-Filing Portal:
  1. Log in to the Income Tax Portal.
  2. Go to e-File > e-Pay Tax.
  3. Select the “Payment History” tab to view and download past challan receipts.
• Annual Information Statement (AIS) / Form 26AS: These tax credit statements automatically reflect the serial number once the bank uploads the data (usually within 3–7 days).
• Net Banking: Most banks allow you to “Regenerate Challan” or view “Tax Payment History” within their portal to retrieve these details.

The Challan Identification Number (CIN) is not a separate number; it is a composite identifier that contains the serial number.

• Format of CIN: A standard CIN is typically an alphanumeric string or a set of details structured as follows:
  • Part 1: 7-digit BSR Code
  • Part 2: 8-digit Date of Deposit (DDMMYYYY)
  • Part 3: 5-digit Challan Serial Number
  Why the numbers might look different
• Alphanumeric strings like  CIN “25051200081591BKID” are often bank-specific transaction IDs or “CIN” as generated by the bank’s internal portal. However, the Income Tax Department requires the official serial number assigned by the Tax Information Network (TIN). 
  How to confirm the official number
• To ensure you have the exact 5-digit number accepted by the ITR portal, check these sources:

  e-Pay Tax History: Log in to the Income Tax Portal, go to e-File > e-Pay Tax > Payment History. Download the “Challan Receipt”; the 5-digit Challan Serial Number will be clearly listed there.

  • Form 26AS: View your Form 26AS via the portal. Under the section for “Advance Tax / Self-Assessment Tax,” the department will display the BSR Code and Challan Serial Number exactly as they need to be entered.
  • OLTAS Inquiry: You can verify your payment details by entering the BSR code, date, and your serial number  on the Challan Status Inquiry (OLTAS) page to see if it matches the department’s records. 
• Extracting the Number: If you have a 20-digit CIN, the last 5 digits are typically your Challan Serial Number.
• Verification: You can use the OLTAS Challan Status Inquiry tool on the Protean (formerly NSDL) website to enter these components and verify if your payment has been successfully received by the Tax Information Network (TIN).

Where to Enter Serial Number in ITR

How to Identify the Correct Number

Retrieving a Missing Serial Number