what is serial number in income tax challan

A challan serial number is a unique identification number assigned to a tax payment challan. It is a 5-digit serial number of the challan in that bank branch on that day. The challan identification number (CIN) contains three parts: the 7-digit BSR code of the bank branch where tax is deposited, the date of deposit (DD/MM/YY) of tax, and the serial number of the challan. The CIN is stamped on the acknowledgement receipt to uniquely identify the tax payment and is required to be quoted in income tax returns or communication with the income tax department whenever required. The CIN has done away with the requirement of attaching a hard copy of tax paid receipts along with income tax returns. Taxpayers can find the challan serial number in the tax payment challan. After successful online payment of income tax, taxpayers receive a CIN number, which is used to get the challan receipt containing the challan number and BSR code. Taxpayers can view and download the challan receipt by logging in to their Income Tax Portal account and navigating to e-File > e-Pay Tax > Payment History tab > Actions > Download.