CRN in income tax stands for Challan Reference Number. It is a unique identification number, typically 14 to 18 digits, generated when a tax challan is created during the process of paying taxes online or offline. The CRN serves as a reference to link the tax payment with the taxpayer's account (such as their PAN), ensuring that the payment is correctly credited and tracked in tax records like Form 26AS. It helps in accurate tax reconciliation, faster payment processing, error reduction in income tax return filing, and provides a clear audit trail for both taxpayers and the tax department. The CRN is generated on the income tax e-filing portal or payment portals and is essential for various tax payments like self-assessment tax, advance tax, TDS, and others.